Jonathan Lai for the Philly Inquirer:

Two years ago this month, Republicans and Democrats in Harrisburg reached a deal on the most significant changes to Pennsylvania election law in decades — including greatly expanded mail voting.

But now, a year after a presidential race in which Donald Trump’s lies about mail voting and Pennsylvania’s results sowed distrust of the electoral system among his supporters, someRepublicans are intensifying efforts to undo a law their party almost universally supported.

The law known as Act 77 is facing perhaps its most serious court challenges yet. Republicans filed two lawsuits this summer saying it violates the state constitution. Democrats had hoped courts would quickly throw them out, but the cases have instead been combined and continue to move forward. The national and state Democratic Party organizations asked Friday to join the litigation in defense of Act 77.

During oral arguments in one case, a panel of judges aggressively questioned lawyers representing the state, in what one Democratic observer described as “skepticism and hostility.” The hearing raised fears among Democrats that the state court might soon rule against the law.

Democratic Gov. Tom Wolf’s administration would almost certainly appeal a loss to the Pennsylvania Supreme Court, where a majority-Democratic bench has generally sided with the state on election issues. But while few believe the Supreme Court would ultimately throw out Act 77, some Democrats and good-government advocates worry that even a temporary loss could create significant challenges.

They worry about how such a setback would be received in a political environment already highly charged on elections issues. And regardless of how the courts rule, they fear the ongoing litigation will continue undermining already-tenuous public trust in the electoral system — just as Republican leaders begin talking with Wolf again about changing election law.