Attorney General Phil Weiser defeated U.S. Sen. Michael Bennet in Colorado’s Democratic primary for governor on Tuesday, overcoming major disadvantages in name ID and campaign spending to send Bennet back to Washington.
The Associated Press called the race for Weiser at 7:55 p.m., when Weiser was leading Bennet by 10 percentage points. Bennet called Weiser to concede about 10 minutes after the race was called.
Weiser will in all likelihood be elected governor in November. Republicans haven’t won a statewide race in Colorado since 2016, and the last GOP candidate for governor lost by nearly 20 percentage points in 2022.
The three-way GOP primary for governor was too close to call at 8:45 p.m.
The winner of Colorado’s gubernatorial race this year will replace term-limited Gov. Jared Polis, a Democrat.
“Together we pushed forward,” Weiser told the crowd at his packed election night watch party in Denver. “We did the hard work. Words cannot convey the gratitude I feel to everybody in this room. This victory belongs to all of you for knocking on doors, for posting on social media, for hosting events, for nudging friends to vote, for so much more. This movement is what democracy looks like.”
Weiser said his campaign proved wrong members of the Democratic establishment who wrote off his bid for governor.
“You all sent a very clear message: the future of Colorado will not be decided by out-of-state billionaires,” he said, pledging to make sure that government “works for all of us, not only the wealthy few.”
When Bennet entered the governor’s race in April 2025, polling showed it was his to lose. Three of Colorado’s four Democrats in the U.S. House quickly got behind his campaign, as did Denver’s mayor and state legislative leaders.
Other prominent Democrats took a pass on the governor’s race in deference to Bennet’s political stature.
But Weiser, who had jumped into the contest months earlier, refused to back down, attacking Bennet for voting to confirm several of President Donald Trump’s appointees while simultaneously — and somewhat confusingly — telling voters Bennet’s Senate seniority was too valuable to lose.
Bennet’s campaign, meanwhile, suffered from what could be called a failure to launch.
“Tonight’s results are not what we wanted,” Bennet, surrounded by his wife and three daughters, said at his campaign’s watch party in downtown Denver. “We came up short. And while that is disappointing — and I’d be lying if I said I wasn’t — I do not regret for a second the campaign that we ran or the cause that we fought for.”
Where Bennet struggled
The senator struggled to spend time on the campaign trail in Colorado because of his responsibilities in Washington. And voters never really felt that he’d answered the question of why he wanted to leave the Senate to become governor — or found it an easy reason not to vote for him.
“I think Bennet’s done good things for Colorado,” said Laura Hahn, a Cherry Hills Village Democrat who backed Weiser. “I think he needs to stay in the Senate. That’s where his connections are. He’s a D.C. guy.”
Bennet was still being asked about his effort to leave the Senate up until election day.
“I’m curious to know what prompted you to decide to run for governor when we needed you in the Senate?” a voter asked Bennet two weeks before the primary election during a campaign stop in Englewood.
“Partly, it was where I thought I could be most useful,” Bennet replied.
The voter said afterward that she found Bennet’s answer compelling and that she planned on voting for him in the Democratic primary. But explaining his thinking voter by voter was an impossible path to victory for Bennet.
Adding to Bennet’s problems were questions about how he would handle replacing himself in the Senate and the perception that Weiser was the more progressive choice in the race.
Finally, Bennet likely lost votes because of anti-incumbent and anti-establishment sentiment among Democratic voters in Colorado and across the nation.
All of those factors working against Bennet gave Weiser, who after eight years as attorney general is hardly a political newcomer, an opening despite his mixed messaging. And also despite the reality that he and Bennet were effectively indistinguishable on policy except for a few issues, like climate and healthcare, where Bennet was actually pushing for more progressive solutions.
How Weiser won
Weiser stayed on message throughout the campaign and became the candidate of all things to all people.
That — paired with his willingness, as one Democratic consultant put it, to drive long distances to give short speeches — allowed him to overcome voters’ familiarity with Bennet.
Jane Robbins, a Centennial Democrat, said she’s been a big fan of Weiser ever since he agreed to talk to her local Indivisible chapter during his first run for attorney general in 2018. When he ran for governor, she never considered supporting Bennet.
“He’s the best,” Robbins said of Weiser on Sunday while preparing to knock on voters’ doors for him in Arapahoe County in the blazing heat.
For instance, in June 2025, Bennet’s campaign released an internal poll showing Bennet leading Weiser by 31 percentage points, with only about 25% of the electorate undecided. Bennet’s lead at that time mostly had to do with voters’ familiarity with him compared to Weiser.
Weiser also overcame a mountain of spending on Bennet’s behalf by the super PAC Rocky Mountain Way. The group raised and spent about $11 million, including more than $5.1 million from former New York Mayor Michael Bloomberg. That money went toward attacking Weiser in TV and digital ads, as well as in mailers.
Rocky Mountain Way and Bennet attacked Weiser for not joining some lawsuits other states’ Democratic attorneys general had filed against the Trump administration and for the donations he’s accepted as a candidate and while leading a consortium of attorneys general.
The super PAC supporting Weiser, Fighting for Colorado, raised and spent about $1.4 million.
(Candidates are prohibited from coordinating with super PACs, including raising money on their behalf. But PACs can raise and spend unlimited amounts of money.)
But despite that advantage, Bennet still felt forced to loan his campaign $1 million in the election’s home stretch to try to beat Weiser.
In terms of direct campaign fundraising and spending, Weiser had the clear advantage throughout the election, hauling in about $6.8 million to Bennet’s roughly $5 million, not including the loan.
All of those factors prompted the early lead Bennet had in the race to evaporate.
Bennet’s campaign released an internal poll in June 2025 showing Bennet leading Weiser by 31 percentage points, with only about 25% of the electorate undecided. Over the past year, things changed dramatically.
Last week, Fighting for Colorado released poll results showing Weiser with a comfortable lead.
Bennet appears to be the first sitting U.S. senator to lose a gubernatorial primary since 2010, when Republican Kay Bailey Hutchison lost to incumbent Texas Gov. Rick Perry in the primary.
The Sun couldn’t find another example in modern history of a sitting senator losing a gubernatorial primary.
Bennet’s term in the Senate ends in early 2029. Politically vulnerable after his loss in the governor’s race, it’s unclear if he plans to run for reelection to the Senate in 2028.
Democratic U.S. Sen. John Hickenlooper, Bennet’s junior counterpart in Washington, said Tuesday night that Bennet is “one of the five best senators in the United States.
“I’m going to do everything I can once the dust settles to convince him to reinvest himself in the Senate,” Hickenlooper said at his own watch party, where he easily fended off a primary challenger.
As for why Bennet lost?
“I think Phil got out early. He made a compelling case. He got a lot of the party leadership around the state,” Hickenlooper said. “And he’s been a great attorney general.”
Weiser ended his victory speech Tuesday by thanking Colorado.
“Now, let’s get to work,” he said as the crowd broke out in a roar of claps and hollers, chanting “Phil” to close out the night.
Colorado Sun staff writer John Ingold contributed to this report.