Republican state Sen. Mark Baisley withdrew from the Colorado gubernatorial race last week and announced his candidacy for the U.S. Senate seat held by Democrat John Hickenlooper. His departure leaves 20 Republicans running for the office held by term-limited Democratic Gov. Jared Polis. “Co lorado needs a U.S. Senator who will fight relentlessly for our Constitution, our economy, and our families,” Baisley said in a statement. “After traveling the state and listening to voters, it’s clear that Washington, not just Denver, is where this fight must be taken.” Baisley represents District 4 in the Colorado Senate, which Includes Teller and Park counties. Baisley joins four Republicans hoping to face Hickenlooper in November, including former state Rep. Janak Joshi, R-Colorado Springs, who made an unsuccessful bid for Congress in 2024; retired Marine Col. George Markert, a first-time candidate; Montrose County Commissioner Sean Pond, who declared his candidacy late Sunday; and Dathan Jones, the acting chair of the Alamosa County GOP. Baisley told Colorado Politics that his move was prompted by Democratic state Sen. Julie Gonzales’ decision to challenge Hickenlooper in this year’s primary, suggesting that the incumbent — “the biggest name in politics in Colorado” — might be vulnerable. Baisley added that he believes there remain plenty of “good choices” in the crowded field of Republicans running for governor. “I thought that I was a good option for Colorado for governor, but I also think that there are some other really great options for governor amongst the Republicans,” Baisley said. “So I don’t feel like I’m abandoning my state or putting them in a rough spot, that there’s not a good choice there. There’s several.” Republican candidates for governor include state Sen. Barb Kirkmeyer, R-Brighton; state Rep. Scott Bottoms, R-Colorado Springs; Teller County Sheriff Jason Mikesell; Colorado Springs-based ministry leader Victor Marx; former congressional candidate Joshua Griffin; and conservative podcaster Joe Oltmann. Baisley said he doesn’t plan to make an endorsement in the gubernatorial primary but expects at least a few of his former rivals will support his Senate campaign. Colorado’s Senate race isn’t considered competitive — nonpartisan election forecasters classify it as a safe Democratic seat — but Baisley said he anticipates his entry into the race could draw more national attention to the state, potentially including millions of dollars in outside spending. Republicans haven’t won a statewide election in Colorado since 2016. Hickenlooper, a former two-term governor, unseated the last Republican to occupy one of the state’s Senate seats, Cory Gardner, in 2020. Baisley, who runs Slipglass, a Littleton-based engineering software company, said his contacts in the tech industry prodded him to run for governor and will be on board with his bid for the national office. He also said he was encouraged to jump in the primary by members of the state’s congressional delegation and Colorado GOP Chair Brita Horn. In an interview before his formal announcement, Baisley acknowledged that he has some ground to make up in fundraising, adding that his campaign team hopes to raise $25 million. That’s after bringing in just over $35,000 for his gubernatorial campaign through last year’s third quarter, according to the most recent available campaign finance reports. Although Joshi and Markert reported receipts in the low six figures through the third quarter of 2025, Hickenlooper had raised nearly $6.5 million by the end of September and had more than $3.6 million on hand. Candidates face a Jan. 31 deadline to report fundraising activity through the end of the year. “Obviously, it does take a ton of money,” Baisley said. “I have a new campaign team, and we are setting out to raise $25 million. It’s going to take the institutional money from Washington, but also, I think, the industry folks who will see me see me as good for them, including the aerospace industry.” ...read more read less