Colorado voters selected their Democratic nominees for governor and Senate on Tuesday, June 30, with closely watched primary races testing the party’s direction between establishment and progressive candidates.
In the gubernatorial primary, Colorado Attorney General Phil Weiser faced U.S. Senator Michael Bennet, two statewide elected Democrats competing to succeed term-limited Governor Jared Polis. Weiser, who has served as the state’s top lawyer since 2019, ran an insurgent-style campaign emphasizing his experience leading a large office and his aggressive lawsuits against the Trump administration. Bennet, a three-term senator, entered the race in April 2025 leveraging his name recognition and fundraising infrastructure.
Neither candidate broke 50% in the most recent public polling, with a poll commissioned by a Weiser-supporting group showing the attorney general with a 45% lead among likely Democratic primary voters, according to Colorado Public Radio. The race centered on economic mobility and affordability, with Bennet framing his pitch as necessary to “drive a stake through Trumpism,” while Weiser highlighted his prosecutorial record against the Trump administration.
Millions of dollars flowed into each campaign. Weiser raised about $6.5 million in direct contributions to Bennet’s $4.8 million, though Bennet also loaned his campaign nearly $1 million. A super PAC backing Bennet, Rocky Mountain Way, reported raising more than $11.4 million, with former New York City Mayor Michael Bloomberg contributing $5.1 million of that total. The super PAC supporting Weiser, Fighting for Colorado, raised $1.3 million.
The Democratic nominee will have history on their side in November. Democrats have won all but two gubernatorial races in Colorado over the past 50 years, and every race since 2006.
In the U.S. Senate primary, incumbent John Hickenlooper faced state Senator Julie Gonzales, a progressive challenger representing the Democratic Party’s rising left wing. Hickenlooper, a former Denver mayor and Colorado governor first elected to the Senate in 2020, sought a second term while navigating pressure from the party’s progressive flank. Gonzales, elected to the state senate in 2018 where she serves as Majority Whip, has declined corporate campaign contributions and positioned herself as part of a new generation of Democrats opposing what she calls “do-nothing” incumbents backed by billionaires.
The race reflected a broader pattern in Democratic primaries this year. Progressives scored significant upsets in New York and Maine, mobilizing younger voters and tapping into working-class economic anxieties. Gonzales raised only a tenth of the campaign finances that Hickenlooper accumulated, according to public records, but built a strong grassroots base. Registered Democrats who vote in primaries tend to lean left, favoring Gonzales, though unaffiliated voters—who outnumber both Democrats and Republicans in Colorado—historically favor centrist candidates.
Hickenlooper highlighted his progressive accomplishments in healthcare expansion, housing affordability, environmental protection, and immigration reform while maintaining his centrist identity. He received endorsements from End Citizens United, the League of Conservation Voters, Planned Parenthood Action Fund, and the Greater Metro Denver Ministerial Alliance. Gonzales won backing from Oil Change Action, the Jane Fonda Climate PAC, GenZ for Change, and Faith in Colorado.
The winner of the Senate primary will face Mark Baisley, the de facto Republican nominee after the GOP failed to field any competitors. No Colorado Republican has held a Senate seat since Hickenlooper defeated Cory Gardner in 2020.
Sources
- The Denver Post — detailed reporting on both the gubernatorial and Senate primary races, including candidate backgrounds, campaign spending, and strategic positioning
- Colorado Public Radio — polling data showing Weiser’s lead over Bennet among likely Democratic primary voters
- Reuters — context on the progressive wave in Democratic primaries and the Colorado races
- NBC News — live election results coverage and candidate profiles
- Ballotpedia — candidate information and election framework
