After two Democratic Socialists of America-backed candidates scored upset victories in New York House primaries last week, attention shifted to another closely watched contest on Tuesday night: Colorado's 1st Congressional District Democratic primary.
This time, the political earthquake may have been even bigger.
With roughly 78 percent of the vote reported, Decision Desk HQ projected that 29-year-old attorney Melat Kiros had defeated longtime incumbent Rep. Diana DeGette, ending the congressional career of one of Colorado's most established Democrats. If the projection holds, it would rank among the most significant incumbent primary defeats for House Democrats this election cycle.
Decision Desk HQ projects Melat Kiros wins the CO US House 1 Democratic Primary#DecisionMade: 10:31 PM EDT pic.twitter.com/ExYwfWhKv3
— Decision Desk HQ (@DecisionDeskHQ) July 1, 2026
DeGette, 68, has represented Colorado's heavily Democratic 1st District since 1997, making her the state's longest-serving member of Congress. The district has long been considered safely Democratic, meaning Tuesday's primary was widely viewed as the race most likely to determine who will ultimately represent Denver in Washington.
Although DeGette faced two challengers, Democratic insiders had focused much of their attention on Kiros, a Democratic Socialists of America member whose campaign attracted support from Sen. Bernie Sanders (I-Vt.) and progressive activists looking to push the party further to the left.
Kiros is no stranger to controversy.
Ahead of Colorado's results, read DDHQ's preview of the key races. (link below)
Perhaps the top race is #CO01, where democratic socialist Melat Kiros is primarying longtime Rep. Diana DeGette (D) from the left. This is just the latest left-vs.-establishment clash for Dems. pic.twitter.com/RfhLFZ5nHp
— Decision Desk HQ (@DecisionDeskHQ) June 30, 2026
As previously reported by RedState, critics have pointed to past comments in which she argued that American foreign policy contributed to the conditions that led to the September 11 terrorist attacks. She has also faced criticism over statements regarding Israel and Hamas following the October 7, 2023, terrorist attacks, with opponents accusing her of placing blame on Israel while refusing to condemn antisemitic incidents forcefully.
The social media account DSA Watch also highlighted Kiros' background and policy positions.
According to the account, Kiros immigrated from Ethiopia as an infant and later worked as a corporate attorney before leaving that position after publicly defending pro-Palestinian protests and questioning Israel's right to exist in the aftermath of the October 7 attacks. The account also noted that her platform includes ending all U.S. military aid to Israel, imposing an arms embargo, dismantling ICE, and supporting Medicare for All, while accusing establishment Democrats of profiting from what she describes as "genocide."
The socialists' foreign policy advisor is apparently Osama bin Laden. This is word-for-word how the Taliban justified 9/11. The DSA wants to destroy society altogether. pic.twitter.com/IZHj0h6Veb
— Spencer Pratt (@spencerpratt) June 29, 2026
Those positions have made Kiros a favorite among Democratic Socialists but a deeply polarizing figure among many mainstream Democrats and Republicans alike.
Her victory also adds to what appears to be growing momentum for the Democratic Socialists of America following last week's New York primary wins. Progressive activists have openly celebrated those victories as evidence that left-wing challengers can successfully unseat long-established Democratic incumbents in safely blue districts.
Colorado's 1st District fits that pattern. Because the district strongly favors Democrats in general elections, Kiros now enters the fall campaign as the clear favorite against Republican nominee Christy Peterson, who is making her first run for Congress.
Democrats cheering for elective job losses in their state will never cease to be absolutely wild to me. https://t.co/q8yb2gB8Gm
— Steve Guest (@SteveGuest) June 23, 2026
If Kiros prevails in November, another Democratic Socialist will join the House at a time when the movement is becoming increasingly assertive within Democratic politics.
That confidence has been on display beyond Colorado. Following last week's victories in New York, DSA supporters were seen taunting House Minority Leader Hakeem Jeffries, chanting that he would be "next" on their list of Democratic leaders to defeat. Jeffries is not up for reelection until 2028, assuming he seeks another term, but the message reflected the movement's broader ambition to challenge even the highest-ranking figures within the Democratic Party.