Melat Kiros, a 29-year-old former lawyer and Democratic Socialists of America-endorsed challenger, defeated 15-term Rep. Diana DeGette in Tuesday's Democratic primary for Colorado's First Congressional District, ending DeGette's grip on the Denver-based seat she has held since the mid-1990s.

Kiros led DeGette 49.3 percent to 43.5 percent, with University of Colorado Regent Wanda James at 7.2 percent, when CBS News called the race late Tuesday. Al Jazeera reported the margin as nearly 7,000 votes with 78 percent of ballots counted. The upset extends a summer streak of democratic socialist wins in urban Democratic primaries and reshapes the delegation from a state that has trended Democratic for two decades.

The challenger

Kiros, who moved to the United States from Ethiopia as a baby, had never run for office before this cycle. She was fired from a law firm job after refusing to remove a social media post that criticized firms for their stance on Israel and Palestine, and she has called Israel's actions in Gaza genocide. Her campaign website touts endorsements from the DSA and Sen. Bernie Sanders of Vermont.

Kiros told CBS Colorado she entered the race in part because she had "seen polling that Denverites are more in favor of socialism than they are to capitalism," a reference to a September 2025 Colorado Polling Institute survey in which 52 percent of Denver voters surveyed favored socialism and 48 percent favored capitalism. "I think it's because we're seeing that the way we've organized our government is really only giving returns to the rich and the powerful because they're the ones with the means to influence it in the way that they want to see it, whereas working people do not," she said.

The warning signs

DeGette, the longest-serving member of Colorado's congressional delegation and a senior member of the House Energy and Commerce Committee, had drawn a primary challenger in only five of her 15 elections. At the Denver Democratic Assembly in March, Kiros collected 646 delegate votes, or 63 percent of the total, to DeGette's 336, or 32 percent.

"I was surprised that the congresswoman almost missed getting on the ballot and didn't have, necessarily, a backup plan with signatures," longtime Colorado Democratic strategist Mike Dino told CBS Colorado after the assemblies. "It clearly showed that Melat Kiros was underestimated, but was well-organized, and that's a combination for an upset."

National pattern

The result follows Democratic primary victories by first-time contenders in Maine and New York who beat establishment-backed candidates from the left. In New York City last week, three candidates tied to the DSA and endorsed by Mayor Zohran Mamdani won House primaries. Also Tuesday, Colorado Attorney General Phil Weiser defeated U.S. Sen. Michael Bennet for the Democratic gubernatorial nomination.

DeGette's response was not carried by the wire outlets that reported the projection, and Republican strategists were not quoted in Wednesday's initial coverage. Both source outlets described the First District as overwhelmingly Democratic, and CBS News noted that Republican nominee Christy Peterson ran unopposed, leaving Kiros favored to win the general election.

Kiros will face Peterson on Nov. 3.