Former U.S. President Donald Trump on Thursday slammed the "unprecedented weaponization" of the justice system, hours before he was due to appear in a courtroom to answer charges of conspiring to overturn the 2020 election.

"The Dems don't want to run against me or they would not be doing this unprecedented weaponization of 'Justice.' But soon, in 2024, it will be our turn," he said on his social media platform, Truth Social.

The former president was charged on Tuesday with conspiracy to defraud the United States, conspiracy to obstruct an official proceeding, obstruction of and attempt to obstruct an official proceeding and conspiracy against rights.

Trump, the first former U.S. president to face criminal charges, has been indicted on three separate occasions this year.

In June, special counsel Jack Smith's office charged him in a separate case with illegally retaining classified documents after leaving the White House and obstructing efforts to retrieve them. 

Earlier this year, the Manhattan district attorney's office brought charges that he falsified business records to hide hush money payments to a porn star who claimed to have had an affair with Trump years ago.

Trump has pleaded not guilty in both cases and has portrayed those investigations, as well as the election probes, as part of a coordinated "witch hunt."

In Georgia, the district attorney in Atlanta, Fani Willis, has been investigating whether Trump and his associates illegally interfered with that state's election for more than two years. Willis, an elected Democrat, has signaled she intends to bring charges in that probe within the next three weeks.

Despite the steady drumbeat of scandal, Trump maintains a wide lead over a field of Republican rivals in the November 2024 presidential race, according to public opinion polls.

Strategists said that while the indictments could help Trump solidify support among Republican voters, who view the charges as bogus, they could prove more damaging among independent voters in the general election against Biden.

(With input from agencies)