Kyrsten Lea Sinema ( KEER-stən SIN-ə-mə; born July 12, 1976) is an American politician and former social worker serving as the senior United States senator from Arizona, a seat she has held since 2019. A former member of the Democratic Party, Sinema became an independent in December 2022.Sinema served three terms as a state representative for the 15th legislative district from 2005 to 2011, one term as the state senator for the 15th legislative district from 2011 to 2012, and three terms as the United States representative for the 9th district from 2013 to 2019. She began her political career in the Arizona Green Party and rose to prominence for her progressive advocacy, supporting causes such as LGBT rights and opposing the war on terror. She left the Green Party to join the Arizona Democratic Party in 2004 and was elected to a seat in the United States House of Representatives in 2012. After her election, she joined the New Democrat Coalition, the Blue Dog Coalition and the bipartisan Problem Solvers Caucus, amassing one of the most conservative voting records in the Democratic caucus. Sinema won the 2018 Senate election to replace the retiring Jeff Flake, defeating Republican nominee Martha McSally. She is the first bisexual and the second openly LGBT woman (after Tammy Baldwin) to be elected to Congress, in the House of Representatives in 2012 and in the Senate in 2018. She is also the first woman elected to the Senate from Arizona and the only religiously unaffiliated member of Congress.Sinema was considered a key swing vote in the Senate, which was split 50–50 between Democrats and Republicans in the 117th U.S. Congress. She is one of three independents in the Senate, the others being Bernie Sanders and Angus King, both of whom also caucus with the Democrats. Sinema has announced she will not seek reelection in 2024.