Democratic socialist Melat Kiros has defeated longtime US Representative Diana DeGette in the Democratic primary for Colorado’s 1st Congressional District, ending the incumbent’s nearly three-decade career in Congress.
The race was called on Tuesday, June 30, after results showed Kiros holding a lead of about six percentage points. With 78% of ballots counted, the 29-year-old former attorney was ahead by nearly 7,000 votes, according to media projections.
DeGette, 68, was first elected to the House in 1996 and is currently serving her 15th term. She is Colorado’s longest-serving member of Congress and had previously won reelection comfortably in the Denver-based district.
Kiros celebrated the result before supporters at an election-night gathering, presenting her victory as part of a wider movement challenging the Democratic Party’s established leadership, according to Sabato’s Crystal Ball.
“This is a movement,” Kiros said. “We are just getting started.”
She also thanked DeGette for her work on women’s rights and acknowledged her role in welcoming immigrant families to the district. Kiros moved to the United States from Ethiopia with her family when she was a baby.
Although both candidates were considered progressive on several major policy issues, Kiros argued during the campaign that DeGette had become too closely connected to corporate interests and had not delivered the level of change demanded by Democratic voters.
Kiros campaigned in support of Medicare for All, abolishing US Immigration and Customs Enforcement and ending corporate influence in politics. She also strongly criticized Democratic leaders over US support for Israel and was endorsed by Senator Bernie Sanders and several progressive organizations.
DeGette, meanwhile, emphasized her congressional experience and argued that senior lawmakers were needed to challenge the Trump administration. She received support from prominent members of Colorado’s Democratic establishment but did not issue an immediate public statement after the race was called.
The result adds to a series of primary victories for progressive candidates challenging incumbent Democrats. In New York, Representatives Dan Goldman and Adriano Espaillat recently lost to Brad Lander and Darializa Avila Chevalier, respectively, while other candidates aligned with the Democratic Party’s left wing also secured nominations.
Republican incumbents have faced similar challenges from candidates backed by Trump or associated with the party’s conservative wing. At the state level, Ballotpedia reported that 22 Democratic and 76 Republican legislative incumbents lost their primary races during the 2026 cycle.
Kiros will face Republican Christy Peterson in the November general election. She will enter that contest as the favorite because the Denver-centered district has not elected a Republican to Congress since 1970.