Shortly before Trump made baseless claims at a news conference about massive voter fraud in Pennsylvania, Sen. Pat Toomey, R-Pa., said in a statement that once the state's final election count is "reached and certified, all parties involved must accept the outcome of the election regardless of whether they won or lost."
Toomey on Friday called for patience as the votes are counted, despite Trump's having tweeting earlier Thursday that officials should "stop the count!" Speaking about the mail-in vote count, Trump also told reporters, "There has been a lot of shenanigans, and we can't stand for that in our country."
"It's going to take the time that it takes," he told the TODAY show. "I saw the president's speech last night and it was hard to watch. The president's charges of large-scale fraud, there's no evidence here."
The harshest pushback came from retiring Rep. Will Hurd of Texas.
"A sitting president undermining our political process & questioning the legality of the voices of countless Americans without evidence is not only dangerous & wrong, it undermines the very foundation this nation was built upon," he said in a tweet. "Every American should have his or her vote counted."
Rep. Adam Kinzinger, R-Ill., who at times has been a sharp Trump critic, also offered a strong rebuke.
"We want every vote counted, yes every legal vote (of course). But, if you have legit concerns about fraud present EVIDENCE and take it to court. STOP Spreading debunked misinformation," he wrote. "This is getting insane."
Maryland Gov. Larry Hogan was one of the few Republicans to specifically mention whom he was talking about. "There is no defense for the President's comments tonight undermining our Democratic process. America is counting the votes, and we must respect the results as we always have before. No election or person is more important than our Democracy," he tweeted.
Sen. Mitt Romney of Utah, a vocal Trump critic who was the Republican presidential nominee in 2012, tweeted Friday that the president has the right to ask for recounts and investigations of any alleged irregularities, but is "wrong to say the election was rigged, corrupt and stolen."
Romney said Trump's doing so "damages the cause of freedom here and around the world, weakens the institutions that lie at the foundation of the Republic, and recklessly inflames destructive and dangerous passions."
Romney had called for patience with the voting process in a statement he tweeted Thursday from his personal Twitter account that did not mention the president.
"Counting every vote is at the heart of democracy. That process is often long and, for those running, frustrating. The votes will be counted," Romney wrote then.
Former Rep. Charlie Dent, R-Pa., called Trump's remarks "simply reprehensible."
Rep. Paul Mitchell, R-Mich., offered tough talk and some sympathy in a pair of tweets.
"Every legal vote should and will be counted - as they always are. Where there are issues there are ways to address them. If anyone has proof of wrongdoing, it should be presented and resolved. Anything less harms the integrity of our elections and is dangerous for our democracy.
"I have experienced both losses and victories in elections. Losses hurt deeply - I know that personally. But our nation demands that its political leaders accept both wins and losses with grace and maturity. Let the voters decide," he wrote.
CORRECTION (Nov. 5, 2020, 11.51 p.m. ET): A previous version of this article misstated the state Rep. Paul Mitchell represents. He is from Michigan, not Massachusetts.