DETROIT — Republican election board members in Michigan’s most populous county refused on Tuesday to certify the county’s election results in a nakedly partisan effort to hold up President-elect Joseph R. Biden Jr.’s victory over President Trump — only to reverse themselves after outcry from state officials and Detroit residents who accused them of trying to steal their votes and criticized the move as racist.
The two Republican board members in Wayne County, which includes Detroit and which voted overwhelmingly for Mr. Biden, are white. The Republicans, Monica Palmer and William Hartmann, said they had voted against certifying the results because precincts in the county had conflicting figures for the numbers of votes cast and the number of voters recorded as having participated, even though the disparities mostly involved small numbers of votes.
At one point, Ms. Palmer moved to “certify the results in the communities other than the city of Detroit.”
Mr. Biden won nearly 95 percent of the vote in Detroit, which is more than three-quarters Black. The rest of Wayne County, which voted for Mr. Biden by a smaller margin, is more than three-quarters white.
Mayor Mike Duggan of Detroit accused Republicans of using a racist double standard in targeting small discrepancies in the city when the party’s representatives had no problems certifying heavily white counties that had similar issues.
“You could see the racism in the behavior last night,” Mr. Duggan said at a news conference Wednesday. “American democracy cracked last night, but it didn’t break. But we are seeing a real threat to everything we believe in.”
Ms. Palmer’s motion drew cries of outrage at the meeting, which was held over a Zoom call.
“You look at Black cities and you have extracted a Black city out of the county and said the only one at fault is the city of Detroit, where 80 percent of the people are African-Americans,” the Rev. Wendell Anthony, president of the Detroit chapter of the N.A.A.C.P., shouted on the call, his face almost touching the computer screen.
“Shame on you. You are a disgrace,” he said. “But on Jan. 20, 2021, at twelve noon, no matter what you do, the president of the United States will be Joseph Biden and the vice president, for the first time ever, will be a Black woman named Kamala Harris.”
A Black Detroit resident who attended the meeting, Benita Bradley, asked the Republicans, “Do you know how many young Black teenagers voted for the first time this year? And you sit here and slap those people in the face.”
The initial 2-2 deadlock on the Wayne County Board of Canvassers was among the starkest examples of how previously routine aspects of the nation’s voting system have been tainted by Mr. Trump’s monthslong effort to undermine confidence in the election.
One of the two Democratic members of the board, Jonathan Kinloch, who is Black, said that after the initial vote, he spoke to Ms. Palmer for more than half an hour to try and convince her that certifying the results was the right thing to do and trying to find a way to reach a compromise.
“When it comes to elections, white people don’t understand how ingrained the right to vote is in our conscience,” Mr. Kinloch said. “All those barriers that our grandparents had to do in order to exercise their right to vote that is so easily available to whites in America.”
Neither Republican board member immediately responded to a request for comment on how they came to change their votes.
The office of the Michigan secretary of state, Jocelyn Benson, posted a message on Twitter Wednesday saying “all counties have certified their election results. The Board of State Canvassers is scheduled to meet Nov. 23 to certify the Nov. 3 general election.” Mr. Biden beat Mr. Trump in Michigan by nearly 150,000 votes.