Former President Donald Trump’s indictment Thursday by a New York City grand jury prompted an immediate and divided response from the nation’s lawmakers.

Republicans largely echoed the statements of the former president that he is being targeted by political opponents as he seeks another term in office in 2024.

Democrats were more measured in their response, and an expert in presidential history said the indictment showed the normal functioning of the American legal process.

“There’s nothing in the Constitution that keeps a president, or former president, from being immune from criminal prosecution,” said Margaret O’Mara, chair of American History at the University of Washington who has published on the American presidency.

Still, that process is unprecedented, said Richard Seamon, a constitutional law professor at the University of Idaho. There’s also potential confusion about what the indictment means in the judicial process.

While it’s widely held that a former president can be charged with crimes, Seamon said, the Trump indictment offers a situation “as to which the Constitution is silent.”

“There’s a lot of public misperceptions, that if somebody’s indicted, they’re probably guilty,” Seamon said. “Of course, that’s not really true, and runs counter to the presumption of innocence in the Constitution.”

Trump was indicted for his alleged role in a hush-money payment to conceal an extramarital affair connected to his 2016 campaign, the former president’s lawyers confirmed Thursday.

The development makes Trump the nation’s first commander-in-chief to face criminal charges and threatens to upend the 2024 presidential race as he seeks to return to the White House after his loss in 2020.

The case brought by Manhattan prosecutors is based on a $130,000 payment to adult film actress Stormy Daniels, who claimed she had an affair with the former president. Trump has denied it.

“He did not commit any crime,” Trump’s lawyer Joe Tacopina said in a statement. “We will vigorously fight this political prosecution in court.”

Seamon said it’s also remarkable that the case was brought by the Manhattan district attorney, rather than someone at the federal level.

“What’s particularly striking to me is that this is a local prosecutor,” Seamon said. “This idea that a local prosecutor can prosecute a former president, it seems unusual.”

There’s no provision that prevents someone who’s indicted, or imprisoned, from running for the presidency, O’Mara said, noting that the indictment follows Trump’s announcement that he is running for president in 2024, and many polls have him as the Republican frontrunner. Eugene Debs ran as a socialist for the presidency in 1920 while serving a 10-year prison sentence for sedition.

In the more recent past, comparisons to Richard Nixon – who resigned in August 1974 as the House of Representatives was set to take up articles of impeachment for obstruction of justice in the Watergate scandal – aren’t quite the same, O’Mara said, noting that President Gerald Ford offered Nixon a full pardon in short order. The investigation ended Nixon’s political career, while Trump has vowed to continue campaigning.

“There isn’t really a clear-cut, historical precedent that you can point to,” O’Mara said.

That the indictment was brought even as Trump vows to continue running indicates the grand jury in this case felt the evidence was compelling, O’Mara said.

“I don’t think they would move forward unless there was a preponderance of evidence that would make it a dereliction of their duty not to follow through,” she said.

The prosecutors did not officially announce the indictment Thursday. They are expected to ask Trump to surrender in the coming days and be arraigned, at which point they will announce specific charges.

Former Trump aide Michael Cohen pleaded guilty in 2018 to federal charges of making the payment in exchange for Daniels keeping her claim private. Cohen said he paid Daniels at Trump’s direction and the then-president reimbursed him over the course of several months.

In a statement, Trump repeated a frequent line of attack, accusing Manhattan District Attorney Alvin Bragg of staging a politically motivated prosecution.

“This is political persecution and election interference at the highest level in history,” Trump said. “I believe this witch hunt will backfire massively on Joe Biden.”

Rep. Cathy McMorris Rodgers, in a statement, said it was important for the process to not appear politicized.

“We are in uncharted territory,” McMorris Rodgers said in a statement Thursday night issued through a spokesman. “Even the appearance of this being politically motivated is doing irreparable damage to the trust and confidence in our system. President Trump must receive the same right to due process as every other American.”

Other Congressional Republicans, including some who have sought to distance themselves from Trump since he left office, were quick to criticize Bragg when news of the indictment broke late Thursday, as lawmakers were headed home from the Capitol.

“From day one, the Manhattan District Attorney has been driven not by genuine evidence of wrongdoing, but by political motivations,” Rep. Russ Fulcher, a Republican who represents North Idaho, wrote on Twitter. “Today’s actions have caused irreversible harm to the rule of law, and will further inflame the divisions in our country.”

“The hateful Deep State wants this country to BURN,” Rep. Ronny Jackson, a Texas Republican who served as Trump’s White House physician, wrote on Twitter.

Immediate reactions from Democratic lawmakers were fairly subdued, calling for the legal process to run its course. Some Democrats have expressed concerns that the case against Trump may be relatively weak – although Bragg’s legal argument isn’t yet known – and could resuscitate Trump’s popularity in the GOP primary.

“No politician should be above the law, especially a former president,” Rep. Derek Kilmer, D-Gig Harbor, wrote on Twitter. “The rule of law must be applied equally.”

The division seen in the responses of members of the two parties about the indictment will likely paint public perception of the case, Seamon said, and could further erode trust in America’s legal system.

“I think a lot depends on the perception whether the prosecution is politically motivated,” he said. “To the extent that’s perceived, that could threaten the integrity of the judicial system.”

This story is developing and will be updated.