Tuesday's primaries in Colorado mark the next front in the establishment-versus-insurgent battle playing out within the Democratic Party, one week after major victories for candidates backed by Mayor Zohran Mamdani in New York City. The contests feature three significant matchups where veteran Democrats are facing challenges from progressive insurgents seeking to capitalize on the party's growing anti-Washington sentiment.
In Colorado's 1st District, Rep. Diana DeGette, who has served for nearly 30 years, faces Melot Kiros, a 29-year-old doctoral student and former lawyer who immigrated from Ethiopia as a child. The race represents one of the best opportunities for the progressive wing to unseat an entrenched incumbent.
What the Right Is Saying
DeGette and her allies have emphasized her extensive congressional experience and progressive voting record. The incumbent has sought to burnish her credentials, running ads highlighting her role as an impeachment manager during President Donald Trump's Senate trial following the January 6, 2021, riot at the Capitol, along with her support for Medicare for All and abolishing Immigration and Customs Enforcement.
"I've spent three decades building the relationships and expertise needed to actually deliver results for this district," DeGette said in a recent campaign statement. Her campaign has argued that institutional knowledge matters when navigating complex legislative battles.
Various super PACs have invested more than $2 million to support DeGette, with outside groups framing her as the candidate best positioned to maintain Democratic representation in the historically blue district. Establishment-oriented Democrats have cautioned that primary losses could weaken the party's electoral infrastructure heading into competitive general election cycles.
What the Left Is Saying
Progressive groups backing Kiros argue that DeGette hasn't adequately fought for the district's interests despite her long tenure in Congress. Sen. Bernie Sanders, I-Vt., has endorsed Kiros along with Justice Democrats and the Democratic Socialists of America. These groups have pointed to Kiros as representing a new generation of Democratic voices who will push harder on issues like Medicare for All and immigration reform.
Kiros has argued that DeGette represents an outdated approach to governance. "We need representatives who are actually fighting for working families," Kiros said in campaign materials, noting her background as an immigrant and young professional navigating the district's challenges.
Justice Democrats has invested more than $500,000 to boost Kiros' candidacy, reflecting the group's commitment to supporting candidates who challenge party establishment figures. The group cited last week's New York results as evidence that progressive challengers can win competitive primaries.
What the Numbers Show
Colorado's statewide races also feature significant veteran Democrats on the ballot. Sen. Michael Bennet, who has served since 2009, is competing against Colorado Attorney General Phil Weiser in the race to succeed term-limited Gov. Jared Polis. Both candidates and allied outside groups have launched attacks over their respective approaches to Trump.
In another statewide contest, Democratic Sen. John Hickenlooper faces state Sen. Julie Gonzales, a former Democratic Socialists of America member who has criticized Hickenlooper for voting for 10 of Trump's Cabinet nominees. Hickenlooper has vastly outraised and outspent Gonzales in the race, with his campaign highlighting his work in the Senate and opposition to Trump.
Colorado's 8th District represents the most competitive House seat in the state. In 2024, Trump carried it by less than 2 points, and freshman GOP Rep. Gabe Evans won it by less than 1 point. The Democratic primary features former state Rep. Shannon Bird and state Rep. Manny Rutinel, with Rutinel holding a fundraising advantage and support from labor unions and former Interior Secretary Ken Salazar. According to ad-tracking firm AdImpact, only nine House races have drawn more fall advertising bookings.
The Bottom Line
Tuesday's Colorado primaries will test whether the progressive insurgent wave that succeeded in New York City can translate to other battleground states. The DeGette-Kiros matchup serves as a bellwether for how much appetite Democratic primary voters have for generational change versus experienced incumbents with established voting records.
Voters in all three major Democratic contests will determine nominees who are likely to win easily in November given Colorado's blue-trending electorate. However, the outcomes could shape the party's direction on issues including healthcare, immigration, and Israel policy, particularly in races where progressive challengers have made those topics central to their campaigns.
Polls close at 9 p.m. ET.