By Makini Brice and Jonathan Stempel
WASHINGTON (Reuters) - President Donald Trump's campaign on Monday asked a federal appeals court to revive a long-shot challenge to Pennsylvania's election results, a central part of its effort to stop President-elect Joe Biden's inauguration.
The campaign is appealing a scathing decision on Saturday from a lower court judge who rejected its claims of widespread problems with mail-in ballots in Pennsylvania.
In a filing with the 3rd U.S. Circuit Court of Appeals in Philadelphia, the campaign said it never got a chance to litigate its "serious and well-founded claims" that Democratic officials schemed to ensure Biden's victory by counting potentially tens of thousands of defective mail ballots.
The campaign said U.S. District Judge Matthew Brann should review additional allegations it had dropped from the case but wanted to restore.
It also said if it cannot prevent Pennsylvania's vote from being certified, the state's Republican-led legislature should choose the state's electors.
Biden, a Democrat, won Pennsylvania with about 81,000 more votes than Trump, a Republican.
Even if Trump were ultimately awarded Pennsylvania's 20 electoral votes, he would still need to capture electoral votes in at least two other states that Biden won to claim a second term.
The Trump campaign's appeal is on a fast track.
Pennsylvania Secretary of State Kathy Boockvar, a Democrat responsible for certifying the state's election results, has until Tuesday afternoon to respond to the campaign's filing.
If the campaign loses its appeal, it could ask the U.S. Supreme Court to review the case.
Pennsylvania counties faced a Monday deadline to deliver election results to Boockvar for certification, though some may miss the target.
In his decision on Saturday, Brann said the Trump campaign's case was based on "strained legal arguments" and that he had "no authority to take away the right to vote of even a single person, let alone millions of citizens."
The judge refused to let the campaign add claims to its case, including that its due process rights were violated.
Monday's appeal is focused on the narrow question of whether Brann improperly refused to let the campaign amend its lawsuit a second time.
In its filing, Trump's campaign denied trying to disenfranchise Pennsylvania's roughly 6.8 million voters.
It said it wanted an expert to "sample" the 1.5 million mail ballots, figure out how many overall were defective and have those "deducted from Biden's votes, which may change the result of the election."
The campaign did not say that defective ballots favoring Trump should also be ignored.
"Certification by state officials is simply a procedural step," Jenna Ellis, a lawyer advising the campaign, said in a statement late on Monday. "Americans must be assured that the final results are fair and legitimate."
Time is running out for Trump. States have until Dec. 8 to meet a "safe harbor" deadline for resolving election disputes and choosing electors, who will convene six days later when the Electoral College formally chooses the next president.
(Reporting by Makini Brice and Jonathan Stempel; Additional reporting by Jan Wolfe; Editing by Noeleen Walder, Tom Brown, Peter Cooney and Cynthia Osterman)