Democratic socialist Melat Kiros triumphed over 15-term Colorado Rep. Diana DeGette on Tuesday, marking one of the most surprising outcomes of the Democratic primary season and contributing to a series of victories for the progressive left.
Kiros’ victory in Colorado’s 1st District unseats a 68-year-old representative who had held the position since before her 29-year-old opponent was born.
This win is reminiscent of Rep. Alexandria Ocasio-Cortez’s (D-N.Y.) remarkable 2018 victory over 10-term incumbent Joe Crowley in New York, providing democratic socialists with renewed energy.
DeGette’s defeat, after representing the district since 1997, was considered improbable in the state not long ago. However, Kiros capitalized on the same anti-incumbent sentiment that recently swept through New York’s Democratic primaries, where Reps. Adriano Espaillat and Dan Goldman were also defeated, showcasing the left’s increasing influence.
The loss is a significant blow to the Democratic establishment, although signs of trouble had been evident for months within DeGette’s campaign. Allies privately admitted the race was tightening, and her team spent weeks urging national Democrats and allied groups for support.
Kiros began her campaign nearly a year ago, positioning it as a generational challenge to the Democratic establishment. She portrayed DeGette, a longtime progressive who served as an impeachment manager against President Donald Trump, as a corporate-backed incumbent disconnected from her constituents and called for a new era of progressive leadership in Congress.
Kiros’ campaign received substantial backing from progressive leaders, including endorsements from Sen. Bernie Sanders and the Working Families Party, as well as support from candidates who recently changed New York’s Democratic delegation.
Her victory marks the seventh primary win this cycle for Justice Democrats, the progressive group that recruited and supported her, making 2026 its most successful primary year to date.
“We are so proud to be sending Colorado’s first Justice Democrat to Congress,” said Alexandra Rojas, executive director of Justice Democrats. “Melat built a movement that inspired Denverites to remember they themselves have the power to transform what kind of Democratic Party they want to be represented by. Melat and our candidates continue winning this cycle because Democratic voters are finally getting leaders acting on their demands.”
In the final days of the campaign, DeGette’s supporters worked frantically to counter Kiros’ momentum, with outside groups injecting approximately $2.3 million into the race over the last month, including $1.3 million in the final days. Despite holding a nearly three-to-one spending advantage, DeGette’s efforts fell short.
DeGette also secured last-minute endorsement videos from Rep. Pramila Jayapal (D-Wash.), a former chair of the Congressional Progressive Caucus, and progressive Rep. Jamie Raskin (D-Md.), who, like DeGette, was a manager of Trump’s impeachments. Still, these efforts proved insufficient to retain her seat.
The new wave of hard-left members in Congress might present challenges for House Minority Leader Hakeem Jeffries (D-N.Y.), especially if Democrats secure a narrow majority in the House this fall.
“If the day comes to vote and he continues taking corporate PAC money, I won’t be voting for him,” Kiros stated in an interview before her victory on Tuesday.

