Democratic socialist Melat Kiros defeated longtime Rep. Diana DeGette in Colorado’s 1st District Democratic primary on Tuesday, marking another victory for the Democratic Party’s growing socialist wing. The Associated Press called the race late Tuesday with Kiros leading DeGette 49.3% to 43.5%, ending the 15-term incumbent’s nearly three decades representing the Denver-area district.

DeGette, 68, has served in Congress since 1997 and warned voters before the primary not to replace her with an inexperienced challenger. Kiros, 29, is a Democratic Socialists of America member, a former attorney, and a Ph.D. student who was backed by Sen. Bernie Sanders. With Colorado’s 1st District considered safely Democratic, she is now heavily favored to win the November general election.

During the campaign, Kiros argued that Democratic leadership had lost touch with working-class voters. “The reality is Democrats have the worst approval rating we’ve had in decades, because we’ve failed to actually do anything for working people,” she said at a candidate forum. She campaigned on Medicare for All, universal child care, publicly financed elections, a “housing first” approach, abolishing ICE, and ending U.S. military aid to Israel.

Kiros has also drawn national attention over several controversial remarks. In a recent interview, she described the Hamas terrorists’ Oct. 7 attack on Israel as an “inevitable consequence” of Israel’s actions. She also said the Sept. 11 terrorist attacks were “inevitable” because of U.S. policy in the Middle East. In 2023, she was fired from the New York office of Sidley Austin after signing an open letter arguing that calls for the elimination of Israel are not antisemitic. She also faced criticism after declining to describe the June 2025 firebombing of a pro-Israel rally in Boulder as antisemitic.

Kiros’s victory follows a string of recent primary wins by democratic socialist and progressive candidates backed by New York City Mayor Zohran Mamdani, adding to signs that the party’s left wing continues to gain momentum in Democratic primaries. Elsewhere in Colorado on Tuesday, incumbent Sen. John Hickenlooper defeated state Sen. Julie Gonzales, a former DSA member, in the Democratic Senate primary.