An election fraud case in Philadelphia has reignited a long-smoldering partisan political issue and stirred up the 2020 presidential race with less than two weeks before the state’s primary.

A South Philadelphia election judge’s March guilty plea to taking bribes to inflate votes for Democratic candidates was kept quiet by federal prosecutors until Thursday, a day after President Donald Trump was again making broad claims about Democratic voter fraud. He offered no evidence to back them up, and threatened to withhold money from states that make it easier to vote by mail.

Trump’s campaign and the Republican National Committee seized on Domenick J. DeMuro’s plea Friday, calling it proof that “voter fraud exists” despite what they said was the news media’s reluctance to report on the issue.

“Democrats have a clear and blatant history of committing voter fraud in Pennsylvania," Melissa Reed, a spokesperson for the RNC and Trump’s campaign, said in a statement. She said the GOP “continues to fight back against the Democrats’ nationwide vote-by-mail push to destroy the integrity of elections.”

But Trump’s campaign, along with the RNC and the Pennsylvania Republican Party, also have been urging voters to sign up for the very vote-by-mail ballots that the president keeps declaring instruments for voter fraud.

It was not clear why U.S. Attorney William M. McSwain, appointed by Trump in 2017, waited more than two months to make the DeMuro case public and did so just before an election. A spokesperson for McSwain declined to comment Friday.

DeMuro, a former judge of elections and Philadelphia Democratic committeeperson, admitted accepting bribes to stuff the ballot box for Democratic candidates from 2014 to 2016. Among the races he sought to influence were the elections of three candidates for Common Pleas Court judge, according to court documents.

In announcing the guilty plea, McSwain said, “Our election system relies on the honesty and the integrity of its election officials. If they are corrupt, the system is corrupt, which creates opportunities for election fraud and for the counting of fake votes.”

DeMuro, according to Board of Elections records, changed his voter registration from Democratic to Republican just before he pleaded guilty. Neither court records nor prosecutors have identified the political consultant who, according to charging documents, paid DeMuro to add votes for Democratic candidates running for the bench and other federal, state, and local offices.

Republicans have long claimed that voter fraud is a rampant, unpunished crime and that restrictions must be put in place to stem the practice. Democrats have pushed back, noting that Republicans who push for legislation that, for instance, requires photo identification to vote offer no evidence of a widespread problem with fraudulent voting.

Trump took this rhetoric to new levels in the run-up to the 2016 presidential election, repeatedly warning the vote would be rigged against him in urban areas like Philadelphia. Even after he won the presidency, Trump claimed, again with no proof, that millions of illegal ballots prevented him from winning the national popular vote.

Voter fraud has been caught and prosecuted in Philadelphia and other jurisdictions. But no evidence exists to prove the crime is rampant.

The Pennsylvania Attorney General’s Office charged four polling place officials in 2017, accusing them of casting bogus ballots and certifying false results during a special election for the state House’s 197th District. Three votes were impacted. They did not change the election’s result, according to prosecutors.

An Inquirer review just before the 2016 presidential election found that nine people had been prosecuted for some version of election fraud in the previous three years. Those cases were filed because polling place officials reported what they saw.

Four polling place officials in the 18th Ward were charged in 2014 with adding six votes to a ballot machine to make the numbers match with the number of voters who signed in that day. Those changes were unlikely to have affected an election’s outcome in an overwhelmingly Democratic ward.

In other cases, a woman voted on behalf of her mother, a polling place official voted for her son and a woman wrote her name in on a ballot being used by another voter.

The city’s largest election fraud case occurred during a 1993 special election for the state Senate’s 2nd District seat. A federal judge threw out every absentee ballot in the race, ruling that election officials had illegally distributed them to campaign and Democratic Party workers. The results of that election were overturned.