The federal indictment of former President Donald J. Trump has unleashed a wave of calls by his supporters for violence and an uprising to defend him, disturbing observers and raising concerns of a dangerous atmosphere ahead of his court appearance in Miami on Tuesday.
In social media posts and public remarks, close allies of Mr. Trump — including a member of Congress — have portrayed the indictment as an act of war, called for retribution and highlighted the fact that much of his base carries weapons. The allies have painted Mr. Trump as a victim of a weaponized Justice Department controlled by President Biden, his potential opponent in the 2024 election.
The calls to action and threats have been amplified on right-wing media sites and have been met by supportive responses from social media users and cheers from crowds, who have become conditioned over several years by Mr. Trump and his allies to see any efforts to hold him accountable as assaults against him.
Experts on political violence warn that attacks against people or institutions become more likely when elected officials or prominent media figures are able to issue threats or calls for violence with impunity. The pro-Trump mob that attacked the Capitol on Jan. 6, 2021, was drawn to Washington in part by a post on Twitter from Mr. Trump weeks earlier, promising that it would be “wild.”
The former president alerted the public to the indictment on Thursday evening in posts on his social media platform, attacking the Justice Department and calling the case “THE GREATEST WITCH HUNT OF ALL TIME.”
“Eye for an eye,” wrote Representative Andy Biggs, Republican of Arizona, in a post on Twitter on Friday. His warning came shortly before the special counsel in the case, Jack Smith, spoke to the public for the first time since he took over the investigation of Mr. Trump’s retention of classified documents.
On Instagram, Mr. Trump’s eldest son’s fiancée, Kimberly Guilfoyle, posted a photo of the former president with the words, “Retribution Is Coming,” in all capital letters.
In Georgia, at the Republican state convention, Kari Lake, who refused to concede the Arizona election for governor in 2022 and who is an ardent defender of Mr. Trump, emphasized that many of Mr. Trump’s supporters owned guns.
“I have a message tonight for Merrick Garland and Jack Smith and Joe Biden — and the guys back there in the fake news media, you should listen up as well, this one is for you,” Ms. Lake said. “If you want to get to President Trump, you are going to have go through me, and you are going to have to go through 75 million Americans just like me. And I’m going to tell you, most of us are card-carrying members of the N.R.A.”
The crowd cheered.
Ms. Lake added: “That’s not a threat, that’s a public service announcement.”
Political violence experts say that even if aggressive language by high-profile individuals does not directly end in physical harm, it creates a dangerous atmosphere in which the idea of violence becomes more accepted, especially if such rhetoric is left unchecked.
“So far, the politicians who have used this rhetoric to inspire people to violence have not been held accountable,” said Mary McCord, a former senior Justice Department official who has studied the ties between extremist rhetoric and violence. “Until that happens, there’s little deterrent to using this type of language.”
The language used by some right-wing media figures was more stark.
On Pete Santilli’s talk show, the conservative provocateur declared that if he were the commandant of the Marine Corps, he would order “every single Marine” to grab President Biden, “throw him in freakin’ zip ties in the back of a freakin’ pickup truck,” and “get him out of the White House.”
One of his guests, Lance Migliaccio, said that if it were legal and he had access, he would “probably walk in and shoot” Gen. Mark A. Milley, the chairman of the Joint Chiefs of Staff and someone Mr. Trump has identified as one of his enemies.
So far, the reactions from Mr. Trump’s supporters have been more intense and explicit than those expressed after Mr. Trump was indicted in a separate case by the Manhattan district attorney Alvin L. Bragg in late March.
Shortly before that indictment, Mr. Trump posted an article on Truth Social, his social media platform, that included a photo of himself holding a baseball bat on one side, and Mr. Bragg in an adjacent photo. Dueling crowds of pro-Trump and anti-Trump protesters appeared in Lower Manhattan when Mr. Trump was arraigned there in April.
On Saturday, in his first public remarks since the latest indictment on seven charges related to the retention of classified documents and efforts to obstruct justice, Mr. Trump attacked those investigating him as engaged in “demented persecution.”
The F.B.I. has been the target of much criticism from far-right Republican lawmakers and the former president’s supporters. In the wake of the heated partisanship, F.B.I. field offices are reporting all threats related to their personnel or facilities to the Washington headquarters, in an unusual step. A law enforcement familiar with the move said the F.B.I. was trying to get a handle on the number of threats around the country directed at the agency.
Despite whatever security precautions are taken for Mr. Trump’s appearance on Tuesday, security experts said that the rhetoric and the threats from it were unlikely to subside and would likely become more pronounced as the case moves forward and the 2024 election nears.
“Rhetoric like this has consequences,” said Timothy J. Heaphy, the lead investigator for the select House committee that investigated the Jan. 6 attack on the Capitol and Mr. Trump’s efforts to remain in the White House after his presidency. “People who we interviewed for the Jan. 6 investigation said they came to the Capitol because politicians and the president told them to be there. Politicians think that when they say things it’s just rhetoric, but people listen to it and take it seriously. In this climate politicians need to realize this and be more responsible.”
On Instagram on Saturday morning, Mr. Trump posted a mash-up video of himself swinging a golf club on the course and an animation of a golf ball hitting President Biden in the head, superimposed with footage of Mr. Biden falling at a public event in recent days after he tripped over something onstage.
It was hardly the first time that figures on the right have issued calls for war or violence to support the former president, or the first time that Mr. Trump has appeared to summon his supporters to amass on his behalf.
In the days leading up to the attack on the Capitol, the notion that a civil war was drawing near was prevalent in right-wing circles. Extremist leaders like Stewart Rhodes, the founder of the Oath Keepers militia, and Enrique Tarrio, the chairman of the Proud Boys, often rallied their groups with incendiary references to the cleansing violence of the American Revolution. Both men have been convicted of sedition in connection with the Capitol attack.
More broadly, on far-right websites, people shared tactics and techniques for attacking the building and discussed building gallows and trapping lawmakers in tunnels there.
The recent bout of warlike language coming in response to Mr. Trump’s indictment echoed what took place among Republican officials and media figures last summer after the F.B.I. searched Mar-a-Lago, Mr. Trump’s private club and residence in Florida, as part of the documents investigation and hauled away about 100 classified records.
“This. Means. War,” The Gateway Pundit, a pro-Trump outlet wrote at the time, setting the tone for others. Hours later, Joe Kent, a Trump-endorsed House candidate in Washington State, went on a podcast run by Stephen K. Bannon, Mr. Trump’s onetime political adviser, and declared, “This just shows everyone what many of us have been saying for a very long time. We’re at war.”
Indeed, within days of the heated language that followed the search of Mar-a-Lago, an Ohio man armed with a semiautomatic rifle tried to breach the F.B.I. field office near Cincinnati and wound up killed in a shootout with the local police.
Jonathan Swan contributed reporting.