Representative Ken Buck, Republican of Colorado, announced on Tuesday that he would leave Congress at the end of next week, cutting short his final term in office in a move that will further shrink his party’s already tiny majority.
The decision, which caught House Republican leaders by surprise, is the latest in a long string of losses for Speaker Mike Johnson and his party, who will control just 218 out of the chamber’s 435 seats after Mr. Buck departs.
In a brief statement, Mr. Buck, a veteran conservative, thanked his constituents and said he hoped to remain involved in the political process while also getting to spend “more time in Colorado with my family.”
Last year Mr. Buck said he would retire at the end of this term, citing his party’s election denialism and the refusal by many Republicans to condemn the Jan. 6, 2021, assault on the Capitol. His plans were seen as unlikely to affect the balance of power in the House, given that Republicans would be all but certain to hold his solidly conservative district in eastern Colorado.
And losing Mr. Buck, who has broken with his party on some major issues — including the recent impeachment of Alejandro N. Mayorkas, the homeland security secretary — was not exactly seen as costing the party a loyal vote.
But Mr. Buck’s decision to leave months before the end of his term on March 22, the same day as the deadline for Congress to pass a package of spending bills to avoid a partial government shutdown, creates yet another headache for House Republicans who have lurched from chaos to crisis for more than a year, leaving them with even less of a cushion to wield their small majority.
Shortly after Mr. Buck’s announcement, Gov. Jared Polis of Colorado said a special election to fill his seat would be held on June 25, aligning with an already scheduled primary for congressional elections in the state.
That leaves several months between Mr. Buck’s exit and the swearing-in of a new, likely Republican, representative.
Republicans currently can afford only two defections on party-line votes, a margin that will not change with Mr. Buck’s departure. But his exit will make the Republican majority even more precarious than it already is, and more vulnerable to inevitable absences caused by personal emergencies, illness, travel delays and any other unforeseen event that would prevent a member from being present on the House floor for votes.
Mr. Buck’s abrupt departure could also scramble the race for control of the House.
Representative Lauren Boebert, the Republican who represents a swing district in western Colorado, had already announced plans to switch districts and run for Mr. Buck’s seat in the more conservative eastern portion of the state. Ms. Boebert won re-election in 2022 by fewer than 600 votes, and seeking Mr. Buck’s seat seemed like an easier path to securing a third term.
But Mr. Buck’s early departure could complicate those plans. If Ms. Boebert tries to run in the special election to replace Mr. Buck and wins her party’s nomination and the race, she will have to resign her current seat, creating another vacancy for Republicans that could not be filled before November. Should she decide against running in the special election — or lose the Republican primary — she would face an uphill race against an incumbent candidate in November.
Colorado’s law governing special elections states that they may not be held within 90 days of a general election, meaning that if she vacated her seat, there would not be time before the November balloting for a special election to replace her.