Who is Kyrsten Sinema?
Kyrsten Sinema is an Arizona politician, attorney, and former social worker who served in the U.S. House of Representatives from 2013 to 2019 and in the U.S. Senate from 2019 to 2025. Over that period she moved from the Democratic Party to registering as an independent, becoming one of the most prominent centrist voices in Washington.
She gained national attention as the first openly bisexual member of the Senate and as a key vote in a narrowly divided chamber, frequently positioning herself as a bridge between Democrats and Republicans on high-profile issues such as infrastructure, gun safety, and economic policy.
Senate Career and Key Legislation
During her six years in the Senate, Sinema helped write and negotiate several major bipartisan laws, including the Bipartisan Infrastructure Law, which funded roads, bridges, broadband, and water projects; the Bipartisan Safer Communities Act on gun safety; the CHIPS and Science Act to boost semiconductor manufacturing; and reforms to the Electoral Count Act intended to strengthen election safeguards.
She also played a decisive role in shaping parts of the Inflation Reduction Act, backing the overall package after securing changes to its tax provisions, and consistently emphasized drought, wildfire mitigation, and long-term water security for the American West in federal negotiations.
Independence and Decision to Leave the Senate
In 2022, Sinema left the Democratic Party and registered as an independent, while continuing to hold committee seats aligned with Democrats, a move that highlighted her emphasis on bipartisanship and institutional norms such as preserving the Senate filibuster.
In 2024, she announced she would not seek reelection, explaining that voters were increasingly rewarding partisan conflict rather than compromise and that her style of politics no longer matched the incentives of the current political climate, opening a highly competitive Senate race in Arizona.
Post-Senate Roles and Ongoing Impact
After leaving office in January 2025, Sinema became President and CEO of the Arizona Business Roundtable, where she works with business and community leaders on issues such as infrastructure, workforce, and economic competitiveness, maintaining a prominent role in Arizona’s policy landscape outside elected office.
She also joined the global law firm Hogan Lovells as a senior advisor in its Government Relations and Public Affairs practice and serves as a Distinguished Professor of Practice at Arizona State University’s School of Social Work, using her legislative experience and academic background to influence public policy, corporate strategy, and the training of future public servants.