Republican Rep. Ken Buck of Colorado, a hardline conservative who has clashed with his own party at times, said Tuesday that he will leave Congress before the end of his term. "Today, I am announcing that I will depart Congress at the end of next week," Buck said in a statement posted to X. The Colorado Republican's departure from the House will shake up the chamber's partisan breakdown, where Republicans control only a very narrow majority -- a major challenge for Speaker Mike Johnson who has frequently been forced to rely on votes from Democrats as well as Republicans to get major pieces of legislation across the finish line. Buck's decision to step down before the end of his term will trim Republicans' slim edge to 218 seats over 213 for Democrats, with three vacancies. With that breakdown, Republicans could only afford to lose two votes to pass legislation on a party-line vote.