Former President Donald Trump and his allies are seizing on routine election processes as signs of fraud in the critical battleground state of Pennsylvania, amplifying allegations, videos and litigation around purported voting irregularities even as local election officials push back.

The playbook is familiar: Like in 2020, Trump campaign's is spreading viral videos of supposed wrongdoing and promising its eager supporters a legal showdown, which experts fear could be used to contest the results of the election if he loses.

Trump supporters spread videos on Tuesday of long lines in Buck County, Pennsylvania, where voters were waiting to request a mail-ballot in person. One social media post from Trump campaign political director James Blair said a line in one area was shut down early around 2:30 p.m.

“This is suppressive and intimidating,” Blair wrote in a post on X seen by 1.8 million people. Elon Musk, the owner of X and a Trump supporter, replied: “Why are they doing this?”

Pennsylvania doesn’t offer in-person early voting. Election officials allow voters to request, fill out and return their mail ballots in person at the county elections office, casting a mail ballot early.

As long lines have formed, officials have been shutting down the line midafternoon so that the office can close as scheduled at 5 p.m., Bucks County spokesman James O’Malley said Tuesday. Unlike on Election Day, there’s no statutory requirement that county offices stay open late for voters in line.

By Tuesday night, Republican National Committee Chairman Michael Whatley told a cheering crowd at a Trump campaign rally in Allentown that the party was going to court against the county.

“I’m proud tonight to tell you that the Trump-Vance campaign has just filed a huge lawsuit against Bucks County for turning away our voters. We are going to fight this thing in court,” he said.

The filing, posted on the docket Wednesday, sought extended hours for requesting mail ballots and a declaration that Bucks County had broken the law.

Bucks County also acknowledged on X that there were some miscommunications with voters on Tuesday, the last day for counties to accept mail-ballot applications, but that voters were allowed to drop off those their applications by 5 p.m.

Whatley championed “victory” on Wednesday after a judge said the county had indeed violated the law and in-person mail ballot applications could continue until Nov. 1.

Nate Persily, an election law professor for NBC News and a Stanford Law School professor, said the Trump campaign is laying the legal groundwork to contest the election if Vice President Kamala Harris wins.

The campaign is “putting down markers to preserve arguments for a potential contest of the election,” he said. “It’s also preparing the public for the likely charges that the election was defective and corrupt — or maybe I should say rigged.”

The Trump campaign had dozens of lawsuits tossed in courts across the country after the 2020 election, with claims ranging from dead voters to hacked voting machines.

“The arguments that were being made in court were inconsistent with each other and there was a sense that they were throwing spaghetti at the wall to see what stuck. It was not difficult for courts to say, where’s the evidence, right?” Persily said. “Right now they are making these accusations more concrete and then trying to lay the groundwork for an objection afterwards if the election is close."

Trump and his supporters have pointed to other incidents in Pennsylvania in recent days to advance a narrative of election fraud.

Trump claimed on Monday night that there were thousands of fake ballots and fraudulent mail ballot applications in two Pennsylvania counties, Lancaster and York. His claims exaggerated Lancaster County officials' admission that they had uncovered — and rejected — hundreds of fraudulent voter registration applications and that other counties were seeing similar applications.

York County officials have said they are reviewing a large batch of voter registration and mail ballot applications, but have so far declined to offer more details.

“Really bad 'stuff.' WHAT IS GOING ON IN PENNSYLVANIA??? Law Enforcement must do their job, immediately!!! WOW!!!” Trump wrote on Truth Social.

Whatley, the RNC chairman, also posted a photo Monday of a woman being arrested at a voting service center in Delaware County, Pennsylvania.

“This is voter suppression from the left. Do not let them turn you away,” he wrote on X.

The woman in question was being “disruptive, belligerent, and attempting to influence voters waiting in line” and was arrested by local police, Delaware County officials said in a statement.

A video of the woman, RNC delegate and volunteer Val Biancaniello, being escorted out in handcuffs was widely shared by Trump allies, including one of those who helped orchestrate similar fraud claims in 2020. The next day, she was side-by-side with Whatley in a video posted on X.

“Lots of voter suppression happening in Delaware County and throughout Pennsylvania. It’s unfortunately — we should have free and fair elections. And this is why it’s so important to elect Donald J. Trump,” she said.

Trump further escalated his voter fraud claims in a post on Truth Social on Wednesday morning.

“Pennsylvania is cheating, and getting caught, at large scale levels rarely seen before. REPORT CHEATING TO AUTHORITIES. Law Enforcement must act, NOW!” the former president wrote.

Pennsylvania Gov. Josh Shapiro responded to the post on X, writing that Trump is using "the same playbook to stoke chaos" he did four years ago.