Chris Christie says he found the case laid out in the indictment ‘devastating.’

Chris Christie, the former Republican governor of New Jersey who is now running for president, called the facts in the indictment against his former ally Donald J. Trump “devastating,” and said that the small group of Republicans now critical of the former president’s conduct would grow.

Mr. Christie, appearing on CNN Friday evening, refuted point-by-point the claim by Mr. Trump and many of his fellow Republicans that the indictment represented selective, partisan prosecution that would unnecessarily divide the country.

The indictment would divide the nation, he said, but Mr. Trump had brought that on himself with poor conduct that “was completely self-inflicted.”

Mr. Christie said he still believes Hillary Clinton should have faced charges in response to her mishandling of classified documents on a private email server, and still does not believe the Trump campaign colluded with Russia in the 2016 election.

But, he added, “Each case needs to be assessed on its own merits, and the facts that are laid out here are damning.”

The prosecution of Mr. Trump is about “holding to account people who are in positions of responsibility,” he said.

Mr. Christie, who opened the broadcast by noting his own record as a federal prosecutor, has made his willingness to draw critical attention to Mr. Trump central to his campaign for the Republican presidential nomination in 2024. But only he and one other candidate, Asa Hutchinson, the former governor of Arkansas, spoke favorably on Friday of the government’s case against the former president.

The other candidates, balancing their need to curry favor with Mr. Trump’s supporters against the imperative to dislodge him as the front-runner, have largely taken the side of the Republican base, which sides with the former president.

Rather than saying the Justice Department is holding Mr. Trump to an unfair standard, Mr. Christie said a man of Mr. Trump’s stature and ambitions should be held to a higher standard.

“The conduct is bad,” he said of actions described in the indictment. “And it is bad for anybody in this country to do it, but it’s particularly awful for someone who has been president and who aspires to be president again.”