Donald Trump denied dozens of criminal counts of willfully mishandling US government secrets and scheming to prevent their return, in a historic first appearance Tuesday in federal court.
It was the former president's second arraignment as he battles a deluge of legal threats, coming just 10 weeks after he was charged with a string of felonies in Manhattan over hush money payments to a porn star.
Trump appeared before a judge in Miami to be formally presented with 37 charges brought by the government following a special counsel probe that opened after an FBI raid of his Florida mansion last August.
"We are certainly entering a plea of not guilty," Todd Blanche, his attorney, told the hearing.
The US government accuses Trump -- who is vying to win back the White House next year -- of violating the Espionage Act and other laws when he removed classified documents upon leaving office and failed to give them up to the National Archives.
Authorities say he conspired to thwart investigators and knowingly shared national security secrets with people who did not have the requisite clearance.
Trump, who flew aboard his private jet to Miami on Monday, is expected to head back afterwards to his golf club in Bedminster, New Jersey, where he plans to deliver a speech protesting his innocence.
"One of the saddest days in the history of our country. We are a nation in decline," Trump posted on his Truth Social platform as he was driven to court.
Miami officials were preparing for large-scale protests, and police ramped up security well in advance of what turned out to be a few dozen Trump supporters converging near the courthouse.
Some wore "Make America Great Again" baseball caps and one with a sign reading "Indict Jack Smith" -- the special prosecutor who brought the charges.
Police, including some on horseback and bicycles, were out in force braced for protests and the possibility of unrest, but the atmosphere was festive with a local radio station blasting Cuban salsa music.
Trump, who made the 25-minute trip from his Doral golf course to the courthouse in a motorcade of at least six black SUVs, earlier lashed out at Smith on Truth Social, calling the prosecutor a "thug" and a "lunatic."
The runaway frontrunner in the 2024 Republican primary has vowed to stay in the race regardless of the outcome of the documents case.
The 49-page indictment, dismissed by Trump as "ridiculous," includes photographs showing boxes of documents stacked at Mar-a-Lago, his Palm Beach residence, in a ballroom and in a bathroom and shower.
Trump, who leads the Republican race for president by more than 30 points has been impeached twice over allegations of misconduct in office and was recently found liable for sexual abuse.
He faces indictment or ongoing scrutiny in four criminal probes -- in Washington, Florida, Georgia and New York -- and could find himself on trial in multiple cases as he campaigns to return to the White House.
The pugnacious billionaire, who turns 77 on Wednesday, continues to defend and even praise the rioters who ransacked the Capitol to halt the certification of the 2020 election and has promised pardons for many if he is reelected.
Trump -- who has repeatedly complained that the investigations against him amount to a baseless "witch hunt" -- vowed Monday to appoint a special prosecutor on his return to office to investigate President Joe Biden and his family.
He appeared in court with strong backing from Republican voters, 81 per cent of whom believe charges against the former president are politically motivated, according to a new Ipsos poll.
"In recent years we have seen the rise of politically-motivated prosecutors who don't care for impartiality, who don't care for due process or equal protection of laws," Trump lawyer Alina Habba told CNN.
"They have been quietly but aggressively cultivating a two-tiered system of justice where selective treatment is the norm."
Republican leaders in Congress and Trump's rivals for the party's presidential nomination have largely glossed over the gravity of the allegations, instead attacking the Justice Department.
The pro-Trump super PAC MAGA Inc launched an ad Monday noting that an ongoing investigation into Biden's own handling of classified documents has not yielded an indictment.
The two cases bear few similarities as Biden is not accused of refusing to return classified documents or suspected of thwarting government attempts to recover them.
