Ron DeSantis says the military is more interested in global warming and “gender ideology” initiatives than in national security.

Tim Scott says the Justice Department “continues to hunt Republicans.”

Vivek Ramaswamy has vowed to “shut down the deep state,” borrowing former President Donald J. Trump’s conspiratorial shorthand for a federal bureaucracy he views as hostile.

As Mr. Trump escalates his attacks on American institutions, focusing his fire on the Justice Department as he faces new criminal charges, his competitors for the Republican nomination have followed his lead.

Several have adopted much of Mr. Trump’s rhetoric sowing broad suspicion about the courts, the F.B.I., the military and schools. As they vie for support in a primary dominated by Mr. Trump, they routinely blast these targets in ways that might have been considered extraordinary, not to mention unthinkably bad politics, just a few years ago.

Yet, there is little doubt about the political incentives behind the statements. Polls show that Americans’ trust in their institutions has fallen to historic lows, with Republicans exhibiting more doubt across a broad swath of public life.

The proliferation of attacks has alarmed both Republicans and Democrats who worry about the long-term impact on American democracy. Public confidence in core institutions — from the justice system to voting systems — is fundamental to a durable democracy, particularly at a time of sharp political division.

“We’ve had these times of division before in our history, but we’ve always had leaders to bridge the gaps who have said we need to build respect, we need to restore confidence in our institutions — today we have just the opposite,” said Asa Hutchinson, the former governor of Arkansas and a moderate whose campaign for the Republican presidential nomination has so far gained little traction.

“That defines the course of 2024. We’re going to have a leader that brings out the best of America, which is the first job of being president. Or you’re going to have somebody that increases distrust that we have in our institutions.”

Mr. Trump is still the loudest voice. As he blames others for his defeat in 2020 and, now, after being charged in three separate criminal cases, he has characterized federal prosecutors as “henchmen” orchestrating a “cover-up.” After he was indicted last week on charges related to his attempts to overturn the election, his campaign cited “abuse, incompetence, and corruption that is running through the veins of our country at levels never seen before.”

Mr. DeSantis, however, has echoed that view, making criticisms of educators, health officials, mainstream media, “elites” and government employees central to his campaign, and even, at times, invoking violent imagery.

“All of these deep state people, you know, we are going to start slitting throats on Day 1,” Mr. DeSantis said during a New Hampshire campaign stop late last week. The governor, a Navy veteran, used similar language about the Department of Defense late last month, saying that if elected he would need a defense secretary who “may have to slit some throats.”

Other candidates, too, have keyed into voters’ trust deficit. Mr. Ramaswamy, a biotech entrepreneur, wants to shut down the F.B.I. and the I.R.S. as part of his fight against the deep state. Nikki Haley, a former South Carolina governor and ambassador to the United Nations, has said she opposes red-flag gun laws because “I don’t trust that they won’t take them away from people who rightfully deserve to have them.”

Even Mike Pence, who has criticized Mr. Trump’s plot to overturn the 2020 election at the heart of the charges filed late week, has suggested the Justice Department is politically motivated in its prosecution, warning of a “two-tiered system of justice,” with “one set of rules for Republicans, and one set of rules for Democrats.”

Running against the government is hardly new, especially for Republicans. For decades, the party called for shrinking the size and reach of some federal programs — with the exception of the military — and treated President Reagan’s declaration that “government is the problem” as a guiding principle.

But even some Republicans, largely moderates who’ve rejected Trumpism, note the tenor of the campaign rhetoric has reached new and conspiratorial levels. Familiar complaints about government waste or regulatory overreach are now replaced with claims that government agencies are targeting citizens and that bureaucrats are busy enacting political agendas.

“Does anyone believe the IRS won’t go after Middle America?” Nikki Haley tweeted in April.

None of the candidates responded to requests for interviews about these statements.

Casting doubt on the integrity of government is hardly limited to Republican candidates. Robert F. Kennedy Jr., a long-shot candidate for the Democratic nomination, has made questioning public health officials on long-established science a focus of his campaign. In her quixotic bid for the nomination, Marianne Williamson has declared that she is “running to challenge the system.”

And President Biden, whose resistance to institutional change has often frustrated the left wing of his party, has mused about his skepticism of the Supreme Court — “this is not a normal court,” he said, after the court’s ruling striking down affirmative action in college admissions.

A Gallup poll released in July found that public confidence in major American institutions is at record low levels, with historic levels of distrust in the military, police, schools, big business and technology. Several other institutions — including the presidency, the Supreme Court and the criminal justice system as well as newspapers and broadcast news, are just slightly above the record low they hit last year.