A federal appeals court ruling may have torpedoed several federal lawsuits that seek to overturn President Donald Trump’s all-but-certified defeat by former Vice President Joe Biden.

The U.S. Court of Appeals for the Third Circuit ruled Friday that Pennsylvania voters and a congressional candidate could not use certain constitutional arguments to back their claims that some voters were disadvantaged by changes to election rules spurred by the coronavirus pandemic and U.S. Postal System delays.

On Monday, Trump supporters who used similar constitutional arguments in federal lawsuits in Michigan, Pennsylvania, Georgia and Wisconsin voluntarily dismissed their claims.

The dismissals came in advance of Tuesday’s scheduled oral arguments in a federal lawsuit filed by the Trump campaign in Pennsylvania. On Sunday, attorneys for the campaign narrowed their legal arguments in that case to avoid running afoul of the appeals court ruling.

Although the revised complaint still argues 689,472 ballots were improperly processed and counted outside the view of Trump election watchers, it does not not seek legal relief specifically on that point. 

Some election law and constitutional law experts predict that case, too, is in trouble.

“Trump’s legal path to overturn the election results appears 100 percent dead,” Richard Hasen, an election and campaign law expert at the University of California, Irvine, School of Law wrote on his Election Law Blog on Monday.

Even if the Trump campaign succeeded in its slimmed-down arguments in the case to be argued Tuesday, “it does not involve enough ballots to call Pennsylvania’s election results into question,” Hasen said in an email to USA TODAY.

Biden led Trump by 67,353votes in Pennsylvania as of Monday, according to Associated Press tallies.

The Trump campaign’s lawsuit seeks to delay Pennsylvania from certifying its election results. It asks the court to bar certification of results that include absentee and mail ballots that it claims were improperly “cured” of mistakes made by voters, without adequate oversight by Trump campaign monitors. It couldn’t be immediately determined how many ballots are in question.

From the beginning, legal experts said the case had no chance of success. Courts are reluctant to invalidate ballots cast by voters who relied on instructions from election boards, they said, and mail balloting is constitutional and common. 

Analysis:Nine legal experts say Trump’s lawsuit challenging election results in Pennsylvania is dead on arrival

The Trump campaign’s arguments center on the Constitution’s equal protection clause, which requires “equal protection of the laws” for citizens. The pared-down complaint retains an argument based on the U.S. Supreme Court’s Bush v. Gore ruling that decided the 2000 presidential election. 

Appeals court: Bush v. Gore ruling was limited to the 2000 election
The case that went before the appeals court was filed by Republican congressional candidate Jim Bognet and voters who alleged Pennsylvania’s three-day extension for mail and absentee ballots improperly allowed county election boards to accept ballots “that would otherwise be unlawful.”

An appeals court panel denied some of that suit’s constitutional arguments. The court said it did not review the Bush v. Gore decision in evaluating plaintiffs’ equal protection arguments because the Supreme Court said in that ruling it was “limited to the present circumstances” of that case.

“That is a bad sign” for the Pennsylvania case set for arguments on Tuesday, said Kermit Roosevelt, a professor of constitutional law at the University of Pennsylvania Law School in an email.

That case and others are among an explosion of election-related legal challenges that even before Election Day had topped the number of similar federal lawsuits filed during the three prior presidential elections, a USA TODAY analysis found.

Trump’s election challenges haven’t gone far
Trump’s efforts to challenge election results, partly based on allegations of ineligible votes and inadequate observer access to ballot counting, have largely failed. In Pennsylvania alone, Trump supporters have filed at least 15 legal challenges in an effort to reclaim the state’s 20 electoral votes, the Associated Press reported Friday. 

Judges in Pennsylvania, Arizona, Michigan, Georgia, Wisconsin and Nevada, however, have quickly dispatched some of them. A few have been appealed. 

On Friday, Pennsylvania courts dismissed sixTrump campaign lawsuits that argued nearly 9,000 absentee ballots should be disqualified for violations of state election code requirements.

Rival appeal petitions were filed over the weekend in those cases.

The four federal lawsuits voluntarily dismissed by voter plaintiffs on Monday in Michigan, Pennsylvania, Georgia and Wisconsin were linked to the law firm of conservative attorney James Bopp Jr. He is a legal consultant for Trump’s 2020 presidential election campaign.

The cases focused on alleged violations of the equal protection clause, as well as constitutional directives on elections and presidential electors. Each of the cases challenged election officials’ inclusion of “illegal presidential elector results in certain counties.”

Trump campaign alleged “two-tiered voting system in Pennsylvania
The Trump campaign’s case set for arguments on Tuesday initially alleged that Pennsylvania used an “illegal, two-tiered voting system” — in-person and mail ballots. It argued that ballots cast in person were devalued because of the extended deadline and a lack of oversight for mail and absentee ballots. 

But after Friday’s appeals court ruling in the other case, Trump campaign lawyers scrapped most of the references to a “two-tiered” voting system, as well as constitutional arguments based on issues other than the equal protection clause. 

The amended complaint alleges that Pennsylvania election officials in areas with heavy Democratic Party enrollment improperly enabled mail voters who had made technical mistakes on their ballots to “cure” the errors. Election officials in other areas of the state followed the law by not providing such assistance, the lawsuit charged.

When the ballots were being counted, election officials in Democratic-majority areas “intentionally denied the Trump Campaign access to unobstructed observation … denying plaintiffs and the residents of Pennsylvania the equal protection of the law.”

Late Monday, the Trump campaign’s lawyers in the case were granted permission by the court to withdraw. They were the second set of lawyers to depart.

The campaign is now being represented by the Harrisburg, Pennsylvania, law firm of Marc Scaringi, whose biography on the firm’s website says he once worked as a part-time radio talk show host.

The Trump campaign asked U.S. District Court Judge Matthew Brann to delay Tuesday’s hearing. Brann denied the motion.