Democrats appear to have held a key Senate seat, with projections indicating Sen. Gary Peters (D-Mich.) prevailed over challenger John James.
Peters beat James by a narrow margin, according to projections from The Associated Press and Decision Desk.
Peters, 61, declared victory late Wednesday.
"Michigan, thank you. It's an honor to serve you for another six years in the U.S. Senate. To all who believed in us, gave your time and effort in our fight: thank you for putting your trust in me. I'm so grateful and energized to keep working to move our state forward," he said in a statement.
But the campaign of James, a 39-year-old businessman, alleged irregularities with the vote count process and he has not conceded.
“There have been a lot of irregularities and a lack of integrity. They’re not letting challengers in, they’re not letting them get food or water. When they do, they’re not letting them come back. There’s all sorts of disruptions to the process.”
The Michigan Secretary of State's website shows James ahead by nearly 235,000 votes with 81 of 83 counties reporting full results.
James had 2.37 million to Peters's 2.14 million.
Michigan election workers were still processing votes throughout Wednesday.
“As votes in Michigan continue to be counted, the presidential race in the state remains extremely tight as we always knew it would be. President Trump’s campaign has not been provided with meaningful access to numerous counting locations to observe the opening of ballots and the counting process, as guaranteed by Michigan law,” Trump campaign manager Bill Stepien said in a statement.
Michigan Secretary of State Jocelyn Benson, a Democrat, responded by saying she was proud of poll workers.
"And let me abundantly clear: we are not going to let any campaign, candidate, or political party stop our work to ensure every voice is heard," Benson said.
Nearly 3.3 million, or about two-thirds of all voters, voted by mail, Benson said in a news conference on Wednesday night.
"I am pleased to announce that in Michigan, the process of tabulation is by and large complete," she added.
Canvassing will take place over the next two weeks.