Feinstein was a staunch advocate for gun control measures, consistently supporting legislation to restrict access to firearms and reduce gun violence.

She championed environmental protection and conservation efforts, supporting legislation to protect California's natural resources and address climate change.

Feinstein dedicated a significant portion of her career to national security and intelligence matters, playing a key role in shaping policies related to counterterrorism, cybersecurity, and intelligence oversight.

She was a supporter of LGBTQ+ rights, consistently voting in favor of legislation promoting equality and non-discrimination.