Michigan MP Paul Mitchell resigned from the Republican Party on Monday because the GOP refused to admit that President Donald Trump lost the election to President-elect Joe Biden.
Mitchell wrote in a damning letter to GOP leaders that Trump's unsubstantiated claims alleging widespread electoral fraud and the Republican Party's tolerance of these claims threatened "long-term damage to our democracy."
"It is unacceptable for political candidates to treat our electoral system as if we were a Third World nation and create suspicion of something as fundamental as the sanctity of our voting," Mitchell wrote to Ronna McDaniel, Chair of the Republican National Committee Minority Chairperson Kevin McCarthy of California.
"Also, it is unacceptable for the President to attack the United States Supreme Court because its Liberal and Conservative justices failed with his side or because" the Court has failed him, "" wrote Mitchell, whose letter was first reported by CNN.
Mitchell will retire from Congress when the current session ends early next year.
Trump has claimed he lost Michigan and several other battlefield states whose votes gave Biden his margin on the electoral college because he illegally suppressed votes for him and artificially inflated Biden's ballot.
The electoral college will meet on Monday, and California's votes have brought Biden over the 270-vote threshold required to win the White House by 5:30 p.m. ET.
Mitchell wrote: "If Republican leaders sit back together and tolerate unsubstantiated conspiracy theories and" stop "the rallies without advocating our electoral process, which the Department of Homeland Security has called" the safest in American history, "our nation will be do corrupt. "
"I have spoken out clearly and firmly against these messages," he wrote.
"However, with the leadership of the Republican Party and our Republican Conference in the House of Representatives actively participating in at least some of these efforts, I fear our democracy will be damaged in the long term."
Mitchell, who represents Michigan's 10th district, said last year he would not seek a third term in Congress and complained that the "rhetoric and vitriol" he saw in Washington overwhelmed the real work of policy making.
Mitchell said that with more than 155 million eligible voters, "both administrative errors and even fraudulent votes are likely to have occurred".
But he also said Trump "didn't lose Michigan to Wayne County," a Democratic stronghold that the president claims counted fraudulent ballots.
"Rather, it lost to dwindling support in areas like Kent and Oakland Counties, both of which were former Republican strongholds," the congressman wrote.
Mitchell said in his letter that he voted for Trump "for about four more years under his leadership despite some reservations."
But he also wrote: "The stability and strength of our democracy is a constant concern of mine."
"I expressed great concern about the president's reaction to Charlottesville, the rhetoric against immigrants they are sending back, and even the racist comments made by my own colleagues in the House."
Even after Mitchell left the GOP, the president and his deputies continued to struggle to undermine public confidence in Biden's victory, arguing that on January 6, Congress would have the final say in choosing the next president.
This is the day that Congress is due to confirm the electoral college vote.
Trump, his campaign and his allies have lost or withdrawn any suit that questioned the validity of Biden's ballot papers. On Friday, the US Supreme Court denied a motion by Texas to file a lawsuit against the voting processes in Michigan, Georgia, Pennsylvania and Wisconsin.
Before the Supreme Court responded to the request, Trump had described the Texas case as "the big one" that would undo Biden's victory.