This past week brought yet another false claim about election fraud here in Pennsylvania, which a hearty band of truth-tellers worked quickly to debunk in the face of the constant headwinds of misinformation coming from Donald Trump World. This time, it was an allegation that election officials in the Keystone State have set the stage for massive cheating in the 2022 midterms by mailing out roughly 250,000 ballots to “unverified voters.”

“No, Pennsylvania didn’t send 255K ballots to ‘unverified’ voters,” The Associated Press’ Angelo Fichera and Ali Swenson reported recently, responding to a report from the conservative Gateway Pundit site — which has been dinged repeatedly for spreading lies — about the mail-in voting process in Pennsylvania, which the former president then blasted out on his Truth Social site. The AP story patiently explained the facts around how some who register to vote here are temporarily tagged as “not verified” until election officials complete the review of their qualifications, which has already been done for all but 7,600 voters and should be done by Election Day.

Apparently the stagecoach or carrier pigeon or whatever carrying the AP’s fact check never made it to the 45th president’s Mar-a-Lago hideout, because one day after this thorough debunking, Trump’s Save America PAC sent out an email blitz that continued to spread the lie, headlined: “ICYMI: ‘Election Integrity Storm Brewing in Pa.’”

The irony here is that for the first time in its existence, the Save America PAC may have been right about something. A storm is brewing over Pennsylvania in the short-term political forecast — arguably a “perfect storm” for a season in which the false conspiracy theories that arose during the election of President Biden in 2020, and which continue to fester, could now swamp the state where U.S. democracy was invented. The key elements are all there: An incredibly close, high-stakes election, a flawed system that slows the counting of the votes, an ongoing legal fight over some of those ballots, and a demagogue who is obsessed with the result.

Despite a number of critical, close races from Georgia to Arizona, key players — especially Trump and his conspiracy-minded supporters — are increasingly fixated on the neck-and-neck Pennsylvania Senate race between the GOP’s Mehmet Oz and Democrat John Fetterman as the place where the 21st-century disease of election denial is likely to fester in the hours and days after the polls close at 8 p.m. on Tuesday. With the 50-50 Senate up for grabs, how this all plays out could determine the balance of power in Washington.

Last month, Rolling Stone reported that while Trump and his minions are looking nationwide at opportunities to spread the chaos of post-election fraud allegations, the Former Guy is especially fixated on the Senate race in Pennsylvania and his unsupported belief there is wholesale election fraud here in Philadelphia, the only place he’s ever lived — during his two years at Penn in the latter 1960s — outside of greater New York and Palm Beach. Trump famously said in a 2020 debate: “Bad things happen in Philadelphia.”

The magazine said Trump seemed fixated on Philly and Pennsylvania at a September Trump Tower meeting with close longtime aide Michael Caputo, Bradford County, Pa., Commissioner Doug McLinko, and retired CIA officer Sam Faddis — calling the state’s election and subsequent vote count “a dress rehearsal for Trump 2024.” Wrote Rolling Stone: “If the Republican does not win by a wide enough margin to trigger a speedy concession from Fetterman — or if the vote tally is close on or after Election Night in November — Trump and other Republicans are already preparing to wage a legal and activist crusade against the ‘election integrity’ of Democratic strongholds such as the Philly area.”

Trump’s Pennsylvania obsession is understandable. Not only is he especially invested in the Oz campaign, after his late endorsement put the celebrity TV doctor just barely over the top in May’s Republican primary, but he knows that Pennsylvania’s divided electorate that was so critical to both his own 2016 Electoral College victory and his 2020 defeat will play the same role in 2024.

But let’s look closer at that perfect storm that will create the climate for any scurrilous allegations over the vote count:

— Most experts and a flood of recent polls suggest the Oz-Fetterman outcome will be very close. An early lead for the Democratic lieutenant governor has shrunk to little or nothing because of constant hammering from Oz over crime and questions about Fetterman’s recovery from a serious stroke in May. It’s the kind of race in which a clear result might not happen on election night under the best of circumstances — and these are not the best of circumstances because...

— Political gridlock in Harrisburg has prevented passage of a common-sense measure so desperately sought by both Democratic and Republican county election officials that would allow them to begin processing the flood of mail-in ballots early, as opposed to the current requirement of not starting until Election Day. That all but guarantees the result will take not hours but days, during which conspiracy theories may flourish, especially because of...

— The new vote-counting phenomenon that experts call either the “the red mirage” or “the blue shift.” It’s been shown repeatedly since the 2020 arrival of the pandemic that Democrats dominate mail-in voting, while Republicans remain much more likely to wait until Election Day to cast their ballot. This creates a scenario in states like Pennsylvania that count the mail-in votes last in which a phantom Republican lead on election night tends to melt away — as happened with Biden and Trump here in 2020. This “red mirage” has proved fertile ground for Republicans to make false claims about a rigged election tally. Another parallel between Biden-Trump and Fetterman-Oz is that...

— A frequent social-media complaint from Facebook-addled, conspiracy-minded Republicans in 2020 was that Biden couldn’t possibly have received 82 million votes because of his age, his lack of large rallies like Trump, or his occasional inarticulateness. If Fetterman takes the lead in the Pa. vote count, you’re going to hear this amplified to the Nth degree with conservatives claiming that the Democrat’s poor post-stroke performance in the Oct. 25 debate means that any victory claim would have to be fraudulent. And finally...

— If the Senate race ends up as close as many expect, the ongoing legal fight over whether to count mail-in ballots that arrive in a timely fashion but with the voter forgetting to write the date on the envelope is going to become a huge factor, and likely fuel widespread anger among whichever side loses the expected court battle.

Election-watchers from the reality-based world say this fight over so-called “election integrity” in Philadelphia and across the Commonwealth will play out on two levels.