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Cook Partisan Voting Index
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Map legend:
State or district has a Cook PVI of D+10 or greater
State or district has a Cook PVI between D+5 and D+10
State or district has a Cook PVI between D+2 and D+5
State or district has a Cook PVI between EVEN and D+2
State or district has a Cook PVI between EVEN and R+2
State or district has a Cook PVI between R+2 and R+5
State or district has a Cook PVI between R+5 and R+10
State or district has a Cook PVI of R+10 or greater
The Cook Partisan Voting Index, abbreviated PVI or CPVI, is a measurement of the partisanship of a U.S. congressional district or U.S. state.[1] This partisanship is indicated as lean towards either the Republican Party or the Democratic Party,[2] compared to the nation as a whole, based on how that district or state voted in the previous two presidential elections.[3][4]
History
[edit]The Partisan Voting Index was developed in 1997 by Charlie Cook of The Cook Political Report, in conjunction with Clark Bensen and his political statistical analysis firm, Polidata, "as a means of providing a more accurate picture of the competitiveness".[5][6][7] It is based on the methodology introduced by Rob Richie of the Center for Voting and Democracy for the Center's July 1997 Monopoly Politics report.[8][9]
The Cook Political Report has since released new PVI scores every two years.[10] In 2021, the newsletter ended its relationship with Polidata and instead used Dave Leip's Atlas of U.S. Presidential Elections to calculate 2020's results.[7] The most recent iteration is the 2025 Cook Partisan Voting Index.[11]
Calculation and format
[edit]The index looks at how every congressional district voted in the past two presidential elections combined and compares it to the national average.[12] The Cook PVI is displayed as a letter, a plus sign, and a number, with the letter (either a D for Democratic or an R for Republican) indicating the party that outperformed in the district and the number showing how many percentage points above the national average it received.[10] In 2022, the formula was updated to weigh the most recent presidential election more heavily than the prior election.[13]
By congressional district
[edit]The PVIs for congressional districts are calculated based on the 2020 and 2024 presidential elections.[11] With a PVI of R+1, California's 22nd congressional district was determined to be the median congressional district, meaning that exactly 217 districts are more Democratic and 217 are more Republican than this district.[11] As of 2025[update], there are 218 districts in the House that are more Republican than the national average and 207 districts more Democratic than the national average. The number of swing seats, defined as those between D+5 and R+5, is 97.[11]
| District | PVI | Party of representative |
|---|---|---|
| Alabama 1 | R+27 | Republican |
| Alabama 2 | D+5 | Democratic |
| Alabama 3 | R+23 | Republican |
| Alabama 4 | R+33 | Republican |
| Alabama 5 | R+15 | Republican |
| Alabama 6 | R+20 | Republican |
| Alabama 7 | D+13 | Democratic |
| Alaska at-large | R+6 | Republican |
| Arizona 1 | R+1 | Republican |
| Arizona 2 | R+7 | Republican |
| Arizona 3 | D+22 | Democratic |
| Arizona 4 | D+4 | Democratic |
| Arizona 5 | R+10 | Republican |
| Arizona 6 | EVEN | Republican |
| Arizona 7 | D+13 | Democratic |
| Arizona 8 | R+8 | Republican |
| Arizona 9 | R+15 | Republican |
| Arkansas 1 | R+23 | Republican |
| Arkansas 2 | R+8 | Republican |
| Arkansas 3 | R+13 | Republican |
| Arkansas 4 | R+20 | Republican |
| California 1 | R+12 | Republican |
| California 2 | D+24 | Democratic |
| California 3 | R+2 | Republican |
| California 4 | D+17 | Democratic |
| California 5 | R+8 | Republican |
| California 6 | D+8 | Democratic |
| California 7 | D+16 | Democratic |
| California 8 | D+24 | Democratic |
| California 9 | D+1 | Democratic |
| California 10 | D+18 | Democratic |
| California 11 | D+36 | Democratic |
| California 12 | D+39 | Democratic |
| California 13 | R+1 | Democratic |
| California 14 | D+20 | Democratic |
| California 15 | D+26 | Democratic |
| California 16 | D+26 | Democratic |
| California 17 | D+21 | Democratic |
| California 18 | D+17 | Democratic |
| California 19 | D+18 | Democratic |
| California 20 | R+15 | Republican |
| California 21 | D+4 | Democratic |
| California 22 | R+1 | Republican |
| California 23 | R+8 | Republican |
| California 24 | D+13 | Democratic |
| California 25 | D+3 | Democratic |
| California 26 | D+8 | Democratic |
| California 27 | D+3 | Democratic |
| California 28 | D+15 | Democratic |
| California 29 | D+20 | Democratic |
| California 30 | D+22 | Democratic |
| California 31 | D+10 | Democratic |
| California 32 | D+17 | Democratic |
| California 33 | D+7 | Democratic |
| California 34 | D+28 | Democratic |
| California 35 | D+8 | Democratic |
| California 36 | D+21 | Democratic |
| California 37 | D+33 | Democratic |
| California 38 | D+10 | Democratic |
| California 39 | D+7 | Democratic |
| California 40 | R+1 | Republican |
| California 41 | R+2 | Republican |
| California 42 | D+18 | Democratic |
| California 43 | D+27 | Democratic |
| California 44 | D+19 | Democratic |
| California 45 | D+1 | Democratic |
| California 46 | D+11 | Democratic |
| California 47 | D+3 | Democratic |
| California 48 | R+7 | Republican |
| California 49 | D+4 | Democratic |
| California 50 | D+16 | Democratic |
| California 51 | D+13 | Democratic |
| California 52 | D+13 | Democratic |
| Colorado 1 | D+29 | Democratic |
| Colorado 2 | D+20 | Democratic |
| Colorado 3 | R+5 | Republican |
| Colorado 4 | R+9 | Republican |
| Colorado 5 | R+5 | Republican |
| Colorado 6 | D+11 | Democratic |
| Colorado 7 | D+8 | Democratic |
| Colorado 8 | EVEN | Republican |
| Connecticut 1 | D+12 | Democratic |
| Connecticut 2 | D+4 | Democratic |
| Connecticut 3 | D+8 | Democratic |
| Connecticut 4 | D+13 | Democratic |
| Connecticut 5 | D+3 | Democratic |
| Delaware at-large | D+8 | Democratic |
| Florida 1 | R+18 | Republican |
| Florida 2 | R+8 | Republican |
| Florida 3 | R+10 | Republican |
| Florida 4 | R+5 | Republican |
| Florida 5 | R+10 | Republican |
| Florida 6 | R+14 | Republican |
| Florida 7 | R+5 | Republican |
| Florida 8 | R+11 | Republican |
| Florida 9 | D+4 | Democratic |
| Florida 10 | D+13 | Democratic |
| Florida 11 | R+8 | Republican |
| Florida 12 | R+17 | Republican |
| Florida 13 | R+5 | Republican |
| Florida 14 | D+5 | Democratic |
| Florida 15 | R+5 | Republican |
| Florida 16 | R+7 | Republican |
| Florida 17 | R+11 | Republican |
| Florida 18 | R+14 | Republican |
| Florida 19 | R+14 | Republican |
| Florida 20 | D+22 | Democratic |
| Florida 21 | R+7 | Republican |
| Florida 22 | D+4 | Democratic |
| Florida 23 | D+2 | Democratic |
| Florida 24 | D+18 | Democratic |
| Florida 25 | D+5 | Democratic |
| Florida 26 | R+16 | Republican |
| Florida 27 | R+6 | Republican |
| Florida 28 | R+10 | Republican |
| Georgia 1 | R+8 | Republican |
| Georgia 2 | D+4 | Democratic |
| Georgia 3 | R+15 | Republican |
| Georgia 4 | D+27 | Democratic |
| Georgia 5 | D+36 | Democratic |
| Georgia 6 | D+25 | Democratic |
| Georgia 7 | R+11 | Republican |
| Georgia 8 | R+15 | Republican |
| Georgia 9 | R+17 | Republican |
| Georgia 10 | R+11 | Republican |
| Georgia 11 | R+12 | Republican |
| Georgia 12 | R+7 | Republican |
| Georgia 13 | D+21 | Democratic |
| Georgia 14 | R+19 | Republican |
| Hawaii 1 | D+13 | Democratic |
| Hawaii 2 | D+12 | Democratic |
| Idaho 1 | R+22 | Republican |
| Idaho 2 | R+13 | Republican |
| Illinois 1 | D+18 | Democratic |
| Illinois 2 | D+18 | Democratic |
| Illinois 3 | D+17 | Democratic |
| Illinois 4 | D+17 | Democratic |
| Illinois 5 | D+19 | Democratic |
| Illinois 6 | D+3 | Democratic |
| Illinois 7 | D+34 | Democratic |
| Illinois 8 | D+5 | Democratic |
| Illinois 9 | D+19 | Democratic |
| Illinois 10 | D+12 | Democratic |
| Illinois 11 | D+6 | Democratic |
| Illinois 12 | R+22 | Republican |
| Illinois 13 | D+5 | Democratic |
| Illinois 14 | D+3 | Democratic |
| Illinois 15 | R+20 | Republican |
| Illinois 16 | R+11 | Republican |
| Illinois 17 | D+3 | Democratic |
| Indiana 1 | D+1 | Democratic |
| Indiana 2 | R+13 | Republican |
| Indiana 3 | R+16 | Republican |
| Indiana 4 | R+15 | Republican |
| Indiana 5 | R+8 | Republican |
| Indiana 6 | R+16 | Republican |
| Indiana 7 | D+21 | Democratic |
| Indiana 8 | R+18 | Republican |
| Indiana 9 | R+15 | Republican |
| Iowa 1 | R+4 | Republican |
| Iowa 2 | R+4 | Republican |
| Iowa 3 | R+2 | Republican |
| Iowa 4 | R+15 | Republican |
| Kansas 1 | R+16 | Republican |
| Kansas 2 | R+10 | Republican |
| Kansas 3 | D+2 | Democratic |
| Kansas 4 | R+12 | Republican |
| Kentucky 1 | R+23 | Republican |
| Kentucky 2 | R+20 | Republican |
| Kentucky 3 | D+10 | Democratic |
| Kentucky 4 | R+18 | Republican |
| Kentucky 5 | R+32 | Republican |
| Kentucky 6 | R+7 | Republican |
| Louisiana 1 | R+19 | Republican |
| Louisiana 2 | D+17 | Democratic |
| Louisiana 3 | R+22 | Republican |
| Louisiana 4 | R+26 | Republican |
| Louisiana 5 | R+18 | Republican |
| Louisiana 6 | D+8 | Democratic |
| Maine 1 | D+11 | Democratic |
| Maine 2 | R+4 | Democratic |
| Maryland 1 | R+8 | Republican |
| Maryland 2 | D+10 | Democratic |
| Maryland 3 | D+12 | Democratic |
| Maryland 4 | D+39 | Democratic |
| Maryland 5 | D+17 | Democratic |
| Maryland 6 | D+3 | Democratic |
| Maryland 7 | D+31 | Democratic |
| Maryland 8 | D+30 | Democratic |
| Massachusetts 1 | D+8 | Democratic |
| Massachusetts 2 | D+13 | Democratic |
| Massachusetts 3 | D+11 | Democratic |
| Massachusetts 4 | D+11 | Democratic |
| Massachusetts 5 | D+24 | Democratic |
| Massachusetts 6 | D+11 | Democratic |
| Massachusetts 7 | D+34 | Democratic |
| Massachusetts 8 | D+15 | Democratic |
| Massachusetts 9 | D+6 | Democratic |
| Michigan 1 | R+11 | Republican |
| Michigan 2 | R+15 | Republican |
| Michigan 3 | D+4 | Democratic |
| Michigan 4 | R+3 | Republican |
| Michigan 5 | R+13 | Republican |
| Michigan 6 | D+12 | Democratic |
| Michigan 7 | EVEN | Republican |
| Michigan 8 | R+1 | Democratic |
| Michigan 9 | R+16 | Republican |
| Michigan 10 | R+3 | Republican |
| Michigan 11 | D+9 | Democratic |
| Michigan 12 | D+21 | Democratic |
| Michigan 13 | D+22 | Democratic |
| Minnesota 1 | R+6 | Republican |
| Minnesota 2 | D+3 | Democratic |
| Minnesota 3 | D+11 | Democratic |
| Minnesota 4 | D+18 | Democratic |
| Minnesota 5 | D+32 | Democratic |
| Minnesota 6 | R+10 | Republican |
| Minnesota 7 | R+18 | Republican |
| Minnesota 8 | R+7 | Republican |
| Mississippi 1 | R+18 | Republican |
| Mississippi 2 | D+11 | Democratic |
| Mississippi 3 | R+14 | Republican |
| Mississippi 4 | R+21 | Republican |
| Missouri 1 | D+29 | Democratic |
| Missouri 2 | R+4 | Republican |
| Missouri 3 | R+13 | Republican |
| Missouri 4 | R+21 | Republican |
| Missouri 5 | D+12 | Democratic |
| Missouri 6 | R+19 | Republican |
| Missouri 7 | R+21 | Republican |
| Missouri 8 | R+27 | Republican |
| Montana 1 | R+5 | Republican |
| Montana 2 | R+15 | Republican |
| Nebraska 1 | R+6 | Republican |
| Nebraska 2 | D+3 | Republican |
| Nebraska 3 | R+27 | Republican |
| Nevada 1 | D+2 | Democratic |
| Nevada 2 | R+7 | Republican |
| Nevada 3 | D+1 | Democratic |
| Nevada 4 | D+2 | Democratic |
| New Hampshire 1 | D+2 | Democratic |
| New Hampshire 2 | D+2 | Democratic |
| New Jersey 1 | D+10 | Democratic |
| New Jersey 2 | R+5 | Republican |
| New Jersey 3 | D+5 | Democratic |
| New Jersey 4 | R+14 | Republican |
| New Jersey 5 | D+2 | Democratic |
| New Jersey 6 | D+5 | Democratic |
| New Jersey 7 | EVEN | Republican |
| New Jersey 8 | D+15 | Democratic |
| New Jersey 9 | D+2 | Democratic |
| New Jersey 10 | D+27 | Democratic |
| New Jersey 11 | D+5 | Democratic |
| New Jersey 12 | D+13 | Democratic |
| New Mexico 1 | D+7 | Democratic |
| New Mexico 2 | EVEN | Democratic |
| New Mexico 3 | D+3 | Democratic |
| New York 1 | R+4 | Republican |
| New York 2 | R+6 | Republican |
| New York 3 | EVEN | Democratic |
| New York 4 | D+2 | Democratic |
| New York 5 | D+24 | Democratic |
| New York 6 | D+6 | Democratic |
| New York 7 | D+25 | Democratic |
| New York 8 | D+24 | Democratic |
| New York 9 | D+22 | Democratic |
| New York 10 | D+32 | Democratic |
| New York 11 | R+10 | Republican |
| New York 12 | D+33 | Democratic |
| New York 13 | D+32 | Democratic |
| New York 14 | D+19 | Democratic |
| New York 15 | D+27 | Democratic |
| New York 16 | D+18 | Democratic |
| New York 17 | D+1 | Republican |
| New York 18 | D+2 | Democratic |
| New York 19 | D+1 | Democratic |
| New York 20 | D+8 | Democratic |
| New York 21 | R+10 | Republican |
| New York 22 | D+4 | Democratic |
| New York 23 | R+10 | Republican |
| New York 24 | R+11 | Republican |
| New York 25 | D+10 | Democratic |
| New York 26 | D+11 | Democratic |
| North Carolina 1 | R+1 | Democratic |
| North Carolina 2 | D+17 | Democratic |
| North Carolina 3 | R+10 | Republican |
| North Carolina 4 | D+23 | Democratic |
| North Carolina 5 | R+9 | Republican |
| North Carolina 6 | R+9 | Republican |
| North Carolina 7 | R+7 | Republican |
| North Carolina 8 | R+10 | Republican |
| North Carolina 9 | R+8 | Republican |
| North Carolina 10 | R+9 | Republican |
| North Carolina 11 | R+5 | Republican |
| North Carolina 12 | D+24 | Democratic |
| North Carolina 13 | R+8 | Republican |
| North Carolina 14 | R+8 | Republican |
| North Dakota at-large | R+18 | Republican |
| Ohio 1 | D+3 | Democratic |
| Ohio 2 | R+24 | Republican |
| Ohio 3 | D+21 | Democratic |
| Ohio 4 | R+18 | Republican |
| Ohio 5 | R+14 | Republican |
| Ohio 6 | R+16 | Republican |
| Ohio 7 | R+5 | Republican |
| Ohio 8 | R+12 | Republican |
| Ohio 9 | R+3 | Democratic |
| Ohio 10 | R+3 | Republican |
| Ohio 11 | D+28 | Democratic |
| Ohio 12 | R+16 | Republican |
| Ohio 13 | EVEN | Democratic |
| Ohio 14 | R+9 | Republican |
| Ohio 15 | R+4 | Republican |
| Oklahoma 1 | R+11 | Republican |
| Oklahoma 2 | R+28 | Republican |
| Oklahoma 3 | R+23 | Republican |
| Oklahoma 4 | R+17 | Republican |
| Oklahoma 5 | R+9 | Republican |
| Oregon 1 | D+20 | Democratic |
| Oregon 2 | R+14 | Republican |
| Oregon 3 | D+24 | Democratic |
| Oregon 4 | D+6 | Democratic |
| Oregon 5 | D+4 | Democratic |
| Oregon 6 | D+6 | Democratic |
| Pennsylvania 1 | D+1 | Republican |
| Pennsylvania 2 | D+19 | Democratic |
| Pennsylvania 3 | D+40 | Democratic |
| Pennsylvania 4 | D+8 | Democratic |
| Pennsylvania 5 | D+15 | Democratic |
| Pennsylvania 6 | D+6 | Democratic |
| Pennsylvania 7 | R+1 | Republican |
| Pennsylvania 8 | R+4 | Republican |
| Pennsylvania 9 | R+19 | Republican |
| Pennsylvania 10 | R+3 | Republican |
| Pennsylvania 11 | R+11 | Republican |
| Pennsylvania 12 | D+10 | Democratic |
| Pennsylvania 13 | R+23 | Republican |
| Pennsylvania 14 | R+17 | Republican |
| Pennsylvania 15 | R+19 | Republican |
| Pennsylvania 16 | R+11 | Republican |
| Pennsylvania 17 | D+3 | Democratic |
| Rhode Island 1 | D+12 | Democratic |
| Rhode Island 2 | D+4 | Democratic |
| South Carolina 1 | R+6 | Republican |
| South Carolina 2 | R+7 | Republican |
| South Carolina 3 | R+21 | Republican |
| South Carolina 4 | R+11 | Republican |
| South Carolina 5 | R+11 | Republican |
| South Carolina 6 | D+13 | Democratic |
| South Carolina 7 | R+12 | Republican |
| South Dakota at-large | R+15 | Republican |
| Tennessee 1 | R+29 | Republican |
| Tennessee 2 | R+17 | Republican |
| Tennessee 3 | R+18 | Republican |
| Tennessee 4 | R+21 | Republican |
| Tennessee 5 | R+8 | Republican |
| Tennessee 6 | R+17 | Republican |
| Tennessee 7 | R+10 | Republican |
| Tennessee 8 | R+21 | Republican |
| Tennessee 9 | D+23 | Democratic |
| Texas 1 | R+25 | Republican |
| Texas 2 | R+12 | Republican |
| Texas 3 | R+10 | Republican |
| Texas 4 | R+16 | Republican |
| Texas 5 | R+13 | Republican |
| Texas 6 | R+14 | Republican |
| Texas 7 | D+12 | Democratic |
| Texas 8 | R+16 | Republican |
| Texas 9 | D+24 | Democratic |
| Texas 10 | R+12 | Republican |
| Texas 11 | R+22 | Republican |
| Texas 12 | R+11 | Republican |
| Texas 13 | R+24 | Republican |
| Texas 14 | R+17 | Republican |
| Texas 15 | R+7 | Republican |
| Texas 16 | D+11 | Democratic |
| Texas 17 | R+14 | Republican |
| Texas 18 | D+21 | Democratic |
| Texas 19 | R+25 | Republican |
| Texas 20 | D+12 | Democratic |
| Texas 21 | R+11 | Republican |
| Texas 22 | R+9 | Republican |
| Texas 23 | R+7 | Republican |
| Texas 24 | R+7 | Republican |
| Texas 25 | R+18 | Republican |
| Texas 26 | R+11 | Republican |
| Texas 27 | R+14 | Republican |
| Texas 28 | R+2 | Democratic |
| Texas 29 | D+12 | Democratic |
| Texas 30 | D+25 | Democratic |
| Texas 31 | R+11 | Republican |
| Texas 32 | D+13 | Democratic |
| Texas 33 | D+19 | Democratic |
| Texas 34 | EVEN | Democratic |
| Texas 35 | D+19 | Democratic |
| Texas 36 | R+18 | Republican |
| Texas 37 | D+26 | Democratic |
| Texas 38 | R+10 | Republican |
| Utah 1 | R+10 | Republican |
| Utah 2 | R+10 | Republican |
| Utah 3 | R+10 | Republican |
| Utah 4 | R+14 | Republican |
| Vermont at-large | D+17 | Democratic |
| Virginia 1 | R+3 | Republican |
| Virginia 2 | EVEN | Republican |
| Virginia 3 | D+18 | Democratic |
| Virginia 4 | D+17 | Democratic |
| Virginia 5 | R+6 | Republican |
| Virginia 6 | R+12 | Republican |
| Virginia 7 | D+2 | Democratic |
| Virginia 8 | D+26 | Democratic |
| Virginia 9 | R+22 | Republican |
| Virginia 10 | D+6 | Democratic |
| Virginia 11 | D+18 | Democratic |
| Washington 1 | D+15 | Democratic |
| Washington 2 | D+12 | Democratic |
| Washington 3 | R+2 | Democratic |
| Washington 4 | R+10 | Republican |
| Washington 5 | R+5 | Republican |
| Washington 6 | D+10 | Democratic |
| Washington 7 | D+39 | Democratic |
| Washington 8 | D+3 | Democratic |
| Washington 9 | D+22 | Democratic |
| Washington 10 | D+9 | Democratic |
| West Virginia 1 | R+22 | Republican |
| West Virginia 2 | R+20 | Republican |
| Wisconsin 1 | R+2 | Republican |
| Wisconsin 2 | D+21 | Democratic |
| Wisconsin 3 | R+3 | Republican |
| Wisconsin 4 | D+26 | Democratic |
| Wisconsin 5 | R+11 | Republican |
| Wisconsin 6 | R+8 | Republican |
| Wisconsin 7 | R+11 | Republican |
| Wisconsin 8 | R+8 | Republican |
| Wyoming at-large | R+23 | Republican |
By state
[edit]The PVIs for states are calculated based on the results of the U.S. presidential elections in 2020 and 2024.[14] The table below reflects the state of Congress and governors, based on the 2024 election results.
| State | PVI | Last presidential election winner |
Party of governor |
Party in Senate |
House balance |
|---|---|---|---|---|---|
| Alabama | R+15 | Republican | Republican | Republican | 5R, 2D |
| Alaska | R+6 | Republican | Republican | Republican | 1R |
| Arizona | R+2 | Republican | Democratic | Democratic | 6R, 3D |
| Arkansas | R+15 | Republican | Republican | Republican | 4R |
| California | D+12 | Democratic | Democratic | Democratic | 43D, 9R |
| Colorado | D+6 | Democratic | Democratic | Democratic | 4D, 4R |
| Connecticut | D+8 | Democratic | Democratic | Democratic | 5D |
| Delaware | D+8 | Democratic | Democratic | Democratic | 1D |
| Florida | R+5 | Republican | Republican | Republican | 20R, 8D |
| Georgia | R+1 | Republican | Republican | Democratic | 9R, 5D |
| Hawaii | D+13 | Democratic | Democratic | Democratic | 2D |
| Idaho | R+18 | Republican | Republican | Republican | 2R |
| Illinois | D+6 | Democratic | Democratic | Democratic | 14D, 3R |
| Indiana | R+9 | Republican | Republican | Republican | 7R, 2D |
| Iowa | R+6 | Republican | Republican | Republican | 4R |
| Kansas | R+8 | Republican | Democratic | Republican | 3R, 1D |
| Kentucky | R+15 | Republican | Democratic | Republican | 5R, 1D |
| Louisiana | R+11 | Republican | Republican | Republican | 4R, 2D |
| Maine | D+4 | Democratic | Democratic | Both[nb 1] | 2D |
| Maryland | D+15 | Democratic | Democratic | Democratic | 7D, 1R |
| Massachusetts | D+14 | Democratic | Democratic | Democratic | 9D |
| Michigan | EVEN | Republican | Democratic | Democratic | 7R, 6D |
| Minnesota | D+3 | Democratic | Democratic | Democratic | 4D, 4R |
| Mississippi | R+11 | Republican | Republican | Republican | 3R, 1D |
| Missouri | R+9 | Republican | Republican | Republican | 6R, 2D |
| Montana | R+10 | Republican | Republican | Republican | 2R |
| Nebraska | R+10 | Republican | Republican | Republican | 3R |
| Nevada | R+1 | Republican | Republican | Democratic | 3D, 1R |
| New Hampshire | D+2 | Democratic | Republican | Democratic | 2D |
| New Jersey | D+4 | Democratic | Democratic | Democratic | 9D, 3R |
| New Mexico | D+4 | Democratic | Democratic | Democratic | 3D |
| New York | D+8 | Democratic | Democratic | Democratic | 19D, 7R |
| North Carolina | R+1 | Republican | Democratic | Republican | 10R, 4D |
| North Dakota | R+18 | Republican | Republican | Republican | 1R |
| Ohio | R+5 | Republican | Republican | Republican | 10R, 5D |
| Oklahoma | R+17 | Republican | Republican | Republican | 5R |
| Oregon | D+8 | Democratic | Democratic | Democratic | 5D, 1R |
| Pennsylvania | R+1 | Republican | Democratic | Both | 10R, 7D |
| Rhode Island | D+8 | Democratic | Democratic | Democratic | 2D |
| South Carolina | R+8 | Republican | Republican | Republican | 6R, 1D |
| South Dakota | R+15 | Republican | Republican | Republican | 1R |
| Tennessee | R+14 | Republican | Republican | Republican | 8R, 1D |
| Texas | R+6 | Republican | Republican | Republican | 25R, 13D |
| Utah | R+11 | Republican | Republican | Republican | 4R |
| Vermont | D+17 | Democratic | Republican | Democratic[nb 2] | 1D |
| Virginia | D+3 | Democratic | Republican | Democratic | 6D, 5R |
| Washington | D+10 | Democratic | Democratic | Democratic | 8D, 2R |
| Washington, D.C. | D+44 | Democratic | Democratic[nb 3] | N/A
|
1D[nb 4] |
| West Virginia | R+21 | Republican | Republican | Republican | 2R |
| Wisconsin | EVEN | Republican | Democratic | Both | 6R, 2D |
| Wyoming | R+23 | Republican | Republican | Republican | 1R |
See also
[edit]- Political party strength in U.S. states
- Psephology, the statistical analysis of elections
- Two-party-preferred vote
Notes
[edit]- ^ Includes an independent senator who caucuses with the Democrats
- ^ Includes an independent senator who caucuses with the Democrats
- ^ Mayor of the District of Columbia
- ^ Non-voting delegate
References
[edit]- ^ Paul, Megan; Zhang, Ruya; Liu, Bian; Saadai, Payam; Coakley, Brian A. (2022). "State-level political partisanship strongly correlates with health outcomes for US children". European Journal of Pediatrics. 181 (1): 273–280. doi:10.1007/s00431-021-04203-y. PMID 34272984.
- ^ Cillizza, Chris (April 10, 2017). "A map that shows we really do live in two different Americas". CNN. Retrieved December 15, 2023.
- ^ Cillizza, Chris (March 14, 2018). "The differences between real grassroots and "Astroturf" matter". CNN. Retrieved November 29, 2020.
Which brings me to the Cook Political Report's Partisan Voting Index or PVI. The goal of the PVI is to compare every congressional district to every other congressional district based on how it has performed in each of the last two presidential elections.
- ^ Benen, Steve (February 7, 2017). "There are 119 Republican House members who should be VERY nervous today". MSNBC. Retrieved November 29, 2020.
To get a sense of a congressional district's political leanings, there's a helpful metric called the Partisan Voter Index, or PVI, created 20 years ago by the Cook Political Report.
- ^ Kurtz, Josh (June 8, 2005). "Future House Opportunities Abound (Maybe)". Roll Call. Retrieved December 22, 2023.
- ^ Daum, Courtenay; Duffy, Robert; Straayer, John, eds. (2011). State of Change. Boulder: University of Colorado Press. ISBN 978-1-4571-1154-9. Retrieved December 22, 2023.
- ^ a b "The Cook Partisan Voting Index (Cook PVI)". The Cook Political Report with Amy Walter. Cook Political Report. Retrieved December 22, 2023.
- ^ Cook, Charlie (August 11, 1997). "New Study Identifies 75 Seats That Should Be In Play for '98 Election". Roll Call. Retrieved January 18, 2024.
- ^ "Monopoly Politics". Center for Voting and Democracy. July 1997. Retrieved January 18, 2024.
- ^ a b Kane, Paul (April 8, 2023). "New report outlines the deep political polarization's slow and steady march". The Washington Post. Retrieved December 22, 2023.
- ^ a b c d Wasserman, David (April 3, 2025). "2025 Cook PVI℠: District Map and List (119th Congress)". Retrieved April 12, 2025.
- ^ Seib, Gerald (December 9, 1998). "GOP Moderates and the Agony Of Their Impeachment Choice". The Wall Street Journal. Retrieved December 22, 2023.
- ^ Wasserman, David (July 13, 2022). "Introducing the 2022 Cook Partisan Voting Index (Cook PVI)". The Cook Political Report with Amy Walter. Retrieved July 13, 2022.
- ^ "2025 Cook PVI℠: State Map and List". Cook Political Report. March 6, 2025. Retrieved May 10, 2025.
External links
[edit]
Wikimedia Commons has media related to Cook PVI.
Cook Partisan Voting Index
View on Grokipediafrom Grokipedia
History and Development
Origins and Introduction
The Cook Partisan Voting Index (PVI) is a statistical measure designed to quantify the partisan lean of individual U.S. congressional districts and states by comparing their presidential election voting patterns to the national average.[1] It provides a standardized score indicating the degree to which a district or state favors one major party over the other, typically expressed in a format such as "R+5" for a 5-point Republican advantage or "D+3" for a Democratic edge, based on averaged results from the two most recent presidential elections.[1] This index serves as a baseline for analysts to evaluate electoral competitiveness, incumbent vulnerability, and partisan shifts independent of specific candidate effects. Developed by Charlie Cook, founder of the independent election analysis firm Cook Political Report (established in 1984), the PVI originated as a tool to address the need for a consistent, data-driven method to assess district-level partisanship amid evolving electoral maps and voter behavior.[8] Cook introduced the index in 1997, drawing on presidential vote shares as a proxy for underlying partisan strength, which he argued offered greater reliability than House election results that could be distorted by local factors like candidate quality or scandals.[1][9] At the time, political forecasting relied heavily on qualitative judgments, and the PVI aimed to inject empirical precision by normalizing district performance against national benchmarks, facilitating comparisons across cycles and geographies.[10] The index's debut coincided with post-1996 election analysis, when redistricting and midterm dynamics highlighted discrepancies between presidential and congressional voting, prompting Cook to formalize a metric that could predict baseline outcomes in future races.[1] Initial applications focused on the 435 House districts, with extensions to states following as data aggregation improved, establishing PVI as a staple in nonpartisan political handicapping despite its origins in a publication known for proprietary ratings. Updates occur after each presidential election and redistricting cycle to reflect new boundaries and voter alignments, ensuring ongoing relevance without altering the core presidential-comparison methodology.[2]Evolution and Updates
The Cook Partisan Voting Index was first introduced in August 1997 by the Cook Political Report to quantify the partisan lean of congressional districts relative to the national average in presidential elections.[1] Initially calculated using data from the two most recent presidential elections with equal weighting, the index has been updated biennially following federal elections and decennial redistricting cycles to reflect shifts in district boundaries and voter behavior.[1] These updates incorporate presidential vote shares from the prior two cycles, averaged against the national benchmark, ensuring the PVI captures evolving partisan baselines without overemphasizing transient national swings.[2] A significant methodological refinement occurred in 2022, coinciding with the 25th anniversary edition and post-2020 redistricting, when the Cook Political Report shifted from equal weighting of the two prior elections to a 3-to-1 emphasis on the most recent cycle (2020 over 2016).[11] This adjustment, aimed at better accounting for recent electoral realignments such as swings among Hispanic voters in states like Florida and Texas, resulted in PVI shifts exceeding 1 point for about 7% of districts, with notable rightward moves in California (11 districts by 2 points) and leftward in Colorado (7 of 8 districts by 1 point).[11] Prior to 2020, calculations relied on data from Polidata, but subsequent versions partnered with Dave Leip's U.S. Election Atlas for precinct-level presidential results, enhancing accuracy for redrawn districts via tools like Dave's Redistricting App and VEST projections.[1] The 2025 edition, released in early April, applies this weighted approach to the 2020 and 2024 presidential results across all 435 House districts and states, revealing a modest national depolarization with fewer extreme PVIs compared to prior cycles.[2] Updates continue to prioritize two-party vote shares to isolate partisan performance from third-party influences, maintaining the index's focus on structural lean over idiosyncratic turnout.[1] This iterative process has sustained the PVI's utility amid gerrymandering and demographic changes, though it requires recalibration after each census to align with new geographic units.Methodology
Data Sources and Calculation
The Cook Partisan Voting Index (PVI) relies on presidential election results as its primary data source, specifically the two-party vote shares for Democratic and Republican candidates in the most recent two presidential elections. For the 2025 edition, this encompasses the 2020 and 2024 elections, with precinct-level data aggregated or estimated to align with current congressional district boundaries following redistricting.[1][5] Prior to 2021, vote data were sourced from Polidata, a vendor providing election results; since then, the Cook Political Report has utilized results from Dave Leip's Atlas of U.S. Presidential Elections for greater accuracy in historical and state-level tabulations. For districts affected by redistricting, 2020 results incorporated into the 2025 PVI were updated using Dave's Redistricting App, which applies Voting Election Science Team (VEST) precinct-level data from the Harvard Dataverse, disaggregated to census blocks where precincts are split across district lines. This methodology ensures vote estimates reflect post-2020 boundary changes without relying on outdated geographies.[1][12][13] Calculation begins by determining each district's or state's average two-party Democratic vote share across the two elections, weighted 75% toward the more recent contest (2024) and 25% toward the prior one (2020) to emphasize current trends. This district-level share is then subtracted from a normalized national two-party Democratic average, set at approximately 50% after weighting the national results from the same elections, yielding the partisan deviation. For instance, a district averaging 57% Democratic two-party support results in a D+7 score (57% - 50% = +7 Democratic lean), while 46% yields R+4 (50% - 46% = +4 Republican lean); scores within 0.5 points of even are classified as EVEN. This formula, refined in recent updates to incorporate weighting, provides a snapshot of partisan performance relative to the nation, updated biennially after presidential cycles and decennial redistricting.[1][5]Format and Score Interpretation
The Cook Partisan Voting Index (PVI) is formatted as a letter followed by a plus sign and a numeric value, such as R+5 or D+3, where "R" denotes a Republican lean and "D" a Democratic lean, or as "Even" for districts or states aligning with the national average.[5] The numeric value represents the absolute difference, in percentage points, between the area's two-party presidential vote share and the national two-party average, averaged across the two most recent presidential elections (2020 and 2024 for the 2025 PVI).[5] [1] A positive score indicates the extent to which the area deviates from national norms in favor of one party; for example, R+5 means the district or state supported the Republican presidential candidate by 5 percentage points more than the national two-party average across those elections, signaling a reliable Republican tilt.[5] Conversely, D+3 reflects a 3-point Democratic advantage over the national benchmark, implying greater resilience to Republican-leaning national environments.[5] Scores near zero, such as Even or R+1, denote competitive areas where outcomes closely track national trends, while absolute values exceeding ±7 typically indicate safe seats for the favored party due to structural partisan advantages.[1] This format enables direct comparisons of partisan strength independent of specific candidate effects, though it assumes presidential voting patterns proxy broader partisan behavior.[1]Applications and Uses
Congressional Districts
The Cook Partisan Voting Index (PVI) quantifies the partisan lean of each of the 435 U.S. congressional districts by comparing their average Democratic two-party presidential vote share from the two most recent elections to the national average. For the 2025 PVI, this uses data from the 2020 and 2024 presidential elections; the difference determines the score, with D+ indicating points above the national Democratic average and R+ points below. Districts within 0.5 points of the national average receive an "EVEN" designation.[2] PVI scores for congressional districts are updated following decennial redistricting and presidential elections to align with current boundaries and voting patterns. This adjustment accounts for changes in district composition due to population shifts or map alterations, providing a consistent measure of underlying partisanship. A district rated R+7, for example, supported the Republican presidential candidate by approximately 7 percentage points more than the nation overall across the two cycles.[1] In practice, congressional PVIs serve as a foundational tool for electoral analysis, identifying districts with leans near EVEN as more susceptible to swings based on national tides or candidate strength, while extreme scores (e.g., beyond R+10 or D+10) signal safe seats resilient to typical partisan shifts. The 2025 index underscores persistent polarization at the district level, with fewer districts exhibiting balanced partisanship compared to prior cycles, reflecting geographic sorting and redistricting effects that concentrate like-minded voters.[2][14] Cook Political Report incorporates district PVIs into its House race ratings, layering them with incumbency advantages, candidate fundraising, and polling to forecast competitiveness. Districts defying their PVI—such as those won by candidates from the minority party—often involve unique local dynamics or national wave elections, as evidenced in past cycles where generic ballot preferences amplified swings in moderate-leaning seats.[1]States and Broader Geography
The Cook Partisan Voting Index (PVI) extends beyond congressional districts to assess partisanship at the state level by comparing each state's average two-party presidential vote share in the prior two elections—2020 and 2024 for the 2025 index—to the national average.[2] A positive score followed by "R+" denotes a Republican lean (e.g., R+14 means the state voted 14 percentage points more Republican than the nation), while "D+" indicates a Democratic lean; scores within 0.5 points of even are classified as EVEN.[15] This state-level application, introduced alongside the district metric in 1997, benchmarks underlying partisan tendencies independent of incumbency or candidate effects, aiding analysis of gubernatorial, senatorial, and legislative races.[1] The 2025 state PVIs reflect a landscape of heightened polarization, with only a handful of states near even: Michigan (R+1), Pennsylvania (R+1), Minnesota (D+1), Nevada (D+1), and New Hampshire (D+1).[15] Solidly Republican states dominate the South, Great Plains, and Mountain West (e.g., West Virginia R+23, Wyoming R+22, North Dakota R+20, Oklahoma R+20), while solidly Democratic states cluster on the coasts and Upper Midwest (e.g., District of Columbia D+43, Vermont D+16, Massachusetts D+15, Hawaii D+15).[15] Compared to 1997, when 26 states fell within R+5 to D+5 (deemed competitive), the number has declined, signaling geographic partisan sorting where voters increasingly self-segregate into ideologically aligned regions.[16]| State/District | 2025 Cook PVI |
|---|---|
| Alabama | R+14 |
| Alaska | R+8 |
| Arizona | R+2 |
| Arkansas | R+16 |
| California | D+13 |
| Colorado | D+4 |
| Connecticut | D+7 |
| Delaware | D+7 |
| District of Columbia | D+43 |
| Florida | R+6 |
| Georgia | R+2 |
| Hawaii | D+15 |
| Idaho | R+18 |
| Illinois | D+7 |
| Indiana | R+11 |
| Iowa | R+7 |
| Kansas | R+10 |
| Kentucky | R+16 |
| Louisiana | R+12 |
| Maine | D+2 |
| Maryland | D+14 |
| Massachusetts | D+15 |
| Michigan | R+1 |
| Minnesota | D+1 |
| Mississippi | R+11 |
| Missouri | R+11 |
| Montana | R+7 |
| Nebraska | R+14 |
| Nevada | D+1 |
| New Hampshire | D+1 |
| New Jersey | D+6 |
| New Mexico | D+6 |
| New York | D+10 |
| North Carolina | R+3 |
| North Dakota | R+20 |
| Ohio | R+6 |
| Oklahoma | R+20 |
| Oregon | D+7 |
| Pennsylvania | R+1 |
| Rhode Island | D+9 |
| South Carolina | R+8 |
| South Dakota | R+16 |
| Tennessee | R+15 |
| Texas | R+5 |
| Utah | R+13 |
| Vermont | D+16 |
| Virginia | D+3 |
| Washington | D+8 |
| West Virginia | R+23 |
| Wisconsin | R+2 |
| Wyoming | R+22 |