Minority Leader Kevin McCarthy and others in House leadership have largely backed Trump as he contests the election results and continues to baselessly claim he won the race.

Sen. Susan Collins on Friday joined the minority of Republicans willing to speak out against the president, saying that by refusing to concede Trump was denying President-elect Joe Biden access to briefings, office space and government resources he would need in the lead up to his inauguration.

Collins also slammed Trump for seeking to "pressure" state election officials working to certify their results, including hosting a delegation of Michigan lawmakers at the White House.

"There is a right way and a wrong way to compile the evidence and mount legal challenges in our courts," the Maine senator said. "The wrong way is to attempt to pressure state election officials. That undermines the public's faith in our election results without evidence and court rulings to support the allegations."

Yet, the number of congressional Republicans willing to go against Trump or his base remains small. Tennessee Sen. Marsha Blackburn — a staunch Trump ally — backpedaled after referring to Biden as "president-elect" in an interview with ABC News on Friday. Her office later told The Tennessean that she "misspoke."

Meanwhile, Trump continues to assert that there was voter fraud without providing evidence. "Big voter fraud information coming out concerning Georgia. Stay tuned!" he tweeted Saturday morning. Georgia certified its results Friday.

A group of Pennsylvania Republican voters and candidates, led by Rep. Mike Kelly, filed a new lawsuit Saturday challenging the vote-by-mail system the state used for the Nov. 3 election and moved to join the Trump campaign’s ongoing federal lawsuit seeking to block certification of the state's presidential election results.

Kelly’s suit filed in the state’s Commonwealth Court early Saturday argues that the vote-by-mail option passed by the state legislature in October 2019 violates the state constitution.

The motion to intervene filed in U.S. District Court in Williamsport, Pa., argues that the mail-in balloting resulted in large numbers of illegally cast ballots, although it’s not clear whether Kelly and his colleagues contend the numbers were sufficient to overturn Biden’s apparent margin of victory in the state of about 82,000 votes. The federal court filing asks that the Pennsylvania legislature be allowed to pick electors for the presidential contest or, alternatively, that the court “order an immediate new election.”

One expert, Trump 2016 campaign aide Matt Braynard, said in a declaration attached to the motion that his analysis of change-of-address data led him to conclude that more than 14,000 mail-in or early voters were not Pennsylvania residents and that at least 742 people voted in Pennsylvania and at least one other state.

However, hours later, the judge tossed the federal case.

The remaining suit is likely to face opposition over the reliability of using change-of-address data from the postal service to determine residency and over the timing of the legal efforts.

The state law broadening eligibility for mail-in voting, Act 77, was passed more than a year ago.

Josh Gerstein contributed reporting.