Rep. Paul Mitchell of Michigan on Monday announced he was withdrawing from the party.
Mitchell said he believes there were "disconcerting aspects" to the presidential election and called for auditing election results, validating ballots, and reporting findings. But he alleged that President Donald Trump and his legal team "have failed to provide substantive evidence of fraud or administrative failure on a scale large enough to impact the outcome of the election."
Candidates are entitled to request recounts and pursue legal challenges, Mitchell added in the letter, but "when entering the political arena, a person must be willing to accept winning and losing with grace and maturity."
Mitchell said he opposed Trump criticizing the Supreme Court and did not appreciate top Republicans participating in efforts like "stop the steal" rallies.
As a result, he said, he is withdrawing from the Republican Party and will henceforth be an independent.
Requests for comment sent to the Republican National Committee and McCarthy's office weren't returned.
Rep. Justin Amash (L-Mich.), another retiring Michigan representative set to leave office soon, last year left the GOP.
“In recent years, though, I’ve become disenchanted with party politics and frightened by what I see from it. The two-party system has evolved into an existential threat to American principles and institutions.”
Mitchell represents Michigan's 10th Congressional District. GOP nominee Lisa McClain won the election to replace Mitchell.