U.S. President Trump meets with Florida Governor DeSantis about coronavirus response at the White House in Washington
U.S. President Donald Trump listens to Florida Governor Ron DeSantis speak about the coronavirus response during a meeting in the Oval Office at the White House in Washington, U.S., April 28, 2020. Reuters

Former President Donald Trump's rivals for the 2024 Republican presidential nomination criticized the move to charge him over his handling of classified documents, underscoring their fear of upsetting the core Trump supporters needed to win the race.

The indictment of a former U.S. president on federal charges is unprecedented in American history, a case made more extraordinary by the fact that Trump is the front-runner in the Republican race to challenge Democratic President Joe Biden next year.

Florida Governor Ron DeSantis and U.S. Senator Tim Scott on Thursday were among the presidential candidates who accused the Justice Department of political bias following news that Trump had been indicted by a federal grand jury for retaining classified documents, obstructing justice and other crimes.

"The weaponization of federal law enforcement represents a mortal threat to a free society," DeSantis, who is running a distant second behind Trump in the polls, wrote on Twitter. "We have for years witnessed an uneven application of the law depending upon political affiliation."

Scott, who is polling in the single digits, also criticized what he called the "weaponization" of federal prosecutors.

"Today what we see is a justice system where the scales are weighted," he said in an interview on Fox News.

A spokesperson for Special Counsel Jack Smith, the Justice Department official who is handling the investigation, declined to comment. It is illegal for the government to comment publicly on any sealed grand jury matter.

Speaking at a White House news conference before the indictment news broke on Thursday, Biden said the public can be confident that the Justice Department acts fairly and with independence, including in its investigation into Trump.

"I have never once, not one single time, suggested to the Justice Department what they should do or not do relative to bringing a charge or not bringing a charge," Biden said in response to a reporter's question.

Vivek Ramaswamy, a venture capitalist running a long-shot bid for the Republican nomination, issued a statement accusing Biden's Justice Department of unfairly targeting the former president and vowing to pardon him if elected.

Former Arkansas Governor Asa Hutchinson, another long-shot candidate, was the sole rival so far to outright criticize Trump. Arguing that Trump had flouted the Constitution and shown a "disrespect for the rule of law," Hutchinson called on him to end his campaign.

Former New Jersey Governor Chris Christie, who this week blasted Trump as he announced his own 2024 bid, said he wanted to see the details of the indictment before weighing in.

"As I have said before, no one is above the law, no matter how much they wish they were," he said on Twitter.

By and large, however, the challengers came to Trump's defense, perhaps mindful of how Trump's March indictment in New York over an alleged hush money payment to a porn star only served to boost his poll numbers. Many Republicans viewed the prosecution as politically charged and rallied to his side.

Rivals are wary of angering Trump's base, which is thought to make up 30% of the Republican electorate and is largely unshakeable in support for Trump.

But Chuck Coughlin, a longtime consultant for Republicans in Arizona, said he believes the cumulative effect of criminal charges will begin to take its toll.

Trump is under investigation in Georgia for allegedly trying to overturn the 2020 election in the state, and faces a separate federal probe into his alleged role in the Jan. 6, 2021 attack on the U.S. Capitol by his supporters.

If the indictments pile up, Coughlin predicts the other Republican candidates will start to argue that Trump cannot win the general election.

"There's got to be a fatigue factor there," Coughlin said. "It has to begin to create pause."