Former President Donald Trump called his federal indictment a “travesty of justice” in his first public appearance since he was charged for allegedly mishandling classified materials after he left the White House.

Trump, the front-runner for the 2024 Republican nomination, drew cheers and applause from about 2,000 delegates at a state GOP convention in Georgia as he denied obstructing justice and claimed without evidence that the indictment was an attempt by President Joe Biden to “jail his leading opponent.”

Trump tried to suggest that the special counsel’s investigation leading up to the indictment unveiled on Friday was a political advantage, saying “the only good thing about it is it has driven my poll numbers way up.”

The former president hit the campaign trail ahead of his expected appearance in a Miami court on Tuesday. He planned to address a state Republican convention in North Carolina later Saturday.

Trump’s appearance in Georgia comes as Fulton County District Attorney Fani T. Willis weighs whether to charge against Trump for his efforts to overturn his 2020 electoral loss to Biden — one of a string of legal entanglements building up for Trump ahead of next year’s election.

The 37-count indictment unsealed by the Justice Department on Friday is a significant escalation of his legal exposure. That opens a lane for Republican rivals to offer themselves as an alternative to Trump’s third bid for the Oval Office.

Trump is the first former US president to face federal allegations of criminal conduct. The indictment, unsealed by a federal court in Miami, outlines 37 counts of seven charges including willful retention of national defense information, corruptly concealing documents, conspiracy to obstruct justice and making false statements.

“This vicious persecution is a travesty of justice,” Trump said Saturday in Columbus, Georgia.

For his part, Biden said Thursday he hadn’t spoken to the Justice Department about the case.

Trump’s base hasn’t been deterred in the past. His fundraising and standing among primary voters surged in April he was indicted in a Manhattan court over alleged hush money payments to adult-film actor Stormy Daniels.

In Georgia, Trump last year failed in an attempt to exact revenge against Republican Governor Brian Kemp and Secretary of State Brad Raffensperger for refusing to alter the results of the 2020 election. Both were reelected, despite facing primary challengers supported by Trump.