"I would be worried if I were her": Democrats fear another loss to the left in Colorado

House Democrats are watching with trepidation as another one of their veteran colleagues tries to fend off a left-wing challenger in the Colorado primaries on Tuesday.

Why it matters: The race will help reveal whether the big anti-establishment victories in New York last week were one-offs or a sign of the new normal for longtime Democratic incumbents.

• Rep. Diana DeGette (D-Colo.) has told colleagues that she thinks she will ultimately prevail over attorney and PhD student Melat Kiros but is taking the challenge seriously, multiple lawmakers told Axios.
• "I think it's quite likely DeGette will lose," said one House Democrat who spoke on the condition of anonymity to offer candid analysis on the race.
• "Democratic leadership that ignores this," the lawmaker added, "does so at its own peril."

State of play: DeGette, a lawyer and former state legislator who has represented her Denver-based House seat since 1997, is facing one of the most serious challenges of her decades-long political career.

• Despite being a Congressional Progressive Caucus member and Medicare-for-All cosponsor, DeGette has been tagged by the left as a defender of Israel and recipient of corporate PAC support.
• DeGette has been endorsed by the co-chairs of the CPC's PAC — Reps. Greg Casar (D-Texas), Maxwell Frost (D-Fla.) and Pramila Jayapal (D-Wash.) — as well as many pro-abortion groups and other establishment-aligned progressive organizations.

Zoom in: Kiros, a 29-year-old Democratic Socialists of America member backed by Sen. Bernie Sanders (I-Vt.) and Rep. Ro Khanna (D-Calif.), was born the same year that DeGette, 68, first took office.

• The Notre Dame law graduate made headlines after being fired by her law firm in 2023 for refusing to take down a Medium post defending pro-Palestinian advocacy and criticizing Israel.
• She has been backed by left-wing groups including DSA, Track AIPAC, the Colorado Working Families Party, Justice Democrats and the Sunrise Movement.

What we're hearing: DeGette told Axios last week that she is "feeling pretty good" about her primary, a sentiment she has also expressed privately in conversations with colleagues.

• "She says [she will be] ok," said a second House Democrat who spoke to Axios anonymously — though personally, they said, "I worry."
• Said a third House Democrat: "She said she thought she would be ok but [is] taking it seriously and she has done all she can."
• "I would be worried if I were her," the third lawmaker said, telling Axios it is "not helpful when Bernie and colleagues endorse against you."

By the numbers: As with most of the marquee races in the 2026 midterms, this primary has attracted millions in outside spending, according to Federal Election Commission filings.

• The largest spender in the race has been Pro-Choice Majority Action, a "pop-up" PAC with ties to the Democratic Women's Caucus and, indirectly, AIPAC. The group has spent over $1.5 million supporting DeGette.
• Another mysterious pop-up super PAC, Mile High Accountability Project, has spent nearly $500,000 backing DeGette.
• Justice Democrats' super PAC has been Kiros' biggest spender at over $500,000, followed by left-wing PAC American Priorities at $150,000, according to FEC reports.

The pro-DeGette ads have largely tried to play up the incumbent's anti-Trump, anti-ICE and overall progressive bona fides, while hitting Kiros for inflammatory past comments.

• Kiros' ads have similarly stressed her opposition to ICE and support for Medicare-for-All, but accused DeGette of being a flawed advocate for progressive priorities due to her funding sources and past pro-Israel votes.

Between the lines: It's not just the Democratic establishment looking at this as a watershed moment. It's all-hands-on-deck for the left as well.

• SF Solidarity, a super PAC founded by left-wing former House candidate Saikat Chakrabarti, filed with the FEC on Monday to spend $26,000 on phone-banking to support Kiros in the final stretch of the campaign.
• "I just supported her on social media again as and she represents a bold new generation of leaders who speak to the moral clarity and fight the party needs," Khanna told Axios.

What to watch: If Kiros wins, she is likely to position herself with a growing bloc of left-wing primary winners, including Darializa Avila Chevalier and Claire Valdez of New York, Chris Rabb of Pennsylvania and Adam Hamawy of New Jersey.

• "If enough of us share that commitment to Medicare for All, to ending corporate capture, to an arms embargo [on Israel], we should absolutely say: here are our conditions," she told Axios. "If you want our votes on leadership, on appropriations, this is what it costs."
• Asked if she would vote for House Minority Leader Hakeem Jeffries (D-N.Y.) as speaker, she said she "will not vote for any Democrat for a leadership position if they take corporate PAC money."
• Leadership is "too cautious, too incremental, and too afraid of upsetting their donors," she added.