Protesters from both sides are gathering outside at Collect Pond Park, some with flags reading “Trump or Death.” Hundreds of people are inside the barricaded park, with pro-Trump supporters outnumbering the anti-Trump protesters and competing voices trading barbs and shouts.

Republican Reps. George Santos and Marjorie Taylor Greene are among the 50 to 60 Trump supporters at the scene.

Greene spoke outside the courthouse calling Trump’s indictment “election interference.”

She accused Manhattan District Attorney Alvin Bragg of being a “tool for Democrats” to “hijack the 2024 presidential election.”

“Every single American should be concerned. They're coming after President Trump today, they will come after you tomorrow. President Trump did nothing wrong,” she said.

Rep. Jamaal Bowman, D-N.Y., who was also outside the courthouse, pushed back, shouting at Greene, "She should not be here."

The streets surrounding the New York Criminal Court are largely blocked off. A robust police presence is busily shepherding onlookers past a row of television cameras.

Greene and Rep. Matt Gaetz, R-Fla., plan to attend Trump's Tuesday night speech at Mar-a-Lago, aides told ABC News.

-ABC News' Lucien Bruggeman, Lauren Peller, Will Steakin and Jay O’Brien

Former President Donald Trump spent Monday night and Tuesday morning huddled with his legal team at Trump Tower preparing for his arraignment, sources told ABC News.

Trump was up early Tuesday morning working the phones and speaking to aides and allies ahead of his Tuesday afternoon arraignment, sources said.

Trump is expected to enter his not guilty plea himself, not through his lawyers, sources said. Trump's legal team has still not seen the indictment or been informed of the charges, according to sources, who told ABC News the legal team expects to see it just minutes before the arraignment begins.

One person described Trump as "upbeat" and "relatively excited." Another person said Trump is "not angry" and is resigned to the fact that this day has finally come.

-ABC News' Katherine Faulders and John Santucci

Former President Donald Trump lashed out at the judge expected to preside over his arraignment in a Tuesday morning post on his social media platform, Truth Social.

Trump attacked the judge and his family, without naming them, claiming they are known Trump haters, and claiming a potential trial would not be fair.

The former president has repeatedly gone after the judge and the Manhattan district attorney on social media in the days leading up to Tuesday's arraignment.

-ABC News' Will Steakin

Just hours before Donald Trump was expected to turn himself in to New York City authorities to face criminal charges, his lawyer Joe Tacopina insisted Friday that the former president will not be pleading guilty.

"Really, there's a lot of mystery here because we're doing something that's never been done before," Tacopina told ABC News’ George Stephanopoulos in an interview on "Good Morning America."

"One thing I can assure you as I sit here today is there will be no guilty plea in this case," he added. "That is one thing I can guarantee you."

Tacopina said Trump won't be put in handcuffs but "he’ll be processed the way anyone else would be, to a degree -- again, with Secret Service involvement."

"I think there will be a typical processing, which does not take long -- 20, 30 minutes," he said. "And then we'll appear before a judge, you know, deal with a couple issues right off the bat and it won't be a long day in court."

That's when authorities will unseal Trump's indictment, revealing the exact charges against him.

"They have not shared it with us, won't share it with us until it's unsealed," Tacopina said. "But we know the basis of the indictment and the factual allegations in the indictment."

Trump's defense team plans to make "a lot of motions" once they see the indictment, according to Tacopina.

"I don't think this case is going to see a jury. I think it's going to go away on papers," he said. "I think there's a legal challenge that will be made and should be made successfully."

When asked about speculation that the judge might impose a gag order, Tacopina said there was "no indication" of that.

"It can't happen in this case," he added. "The defendant is the leading Republican candidate for the office of the president of the United States and will be campaigning. Hard to put a gag order when he's going to be fielding questions about his current legal situation."

After court, Trump plans to travel back to Palm Beach, Florida, where he will make a statement at his Mar-a-Lago estate, according to Tacopina.

The indictment against former President Donald Trump has been unsealed.

Prosecutors allege Trump "employed a 'catch and kill' scheme to identify, purchase, and bury negative information about him and boost his electoral prospects," and "went to great lengths to hide this conduct, causing dozens of false entries in business records to conceal criminal activity, including attempts to violate state and federal election laws."

Prosecutors allege, "In one instance, American Media Inc. ('AMI'), paid $30,000 to a former Trump Tower doorman, who claimed to have a story about a child TRUMP had out of wedlock," though the story wasn't true.

"The People of the State of New York allege that Donald J. Trump repeatedly and fraudulently falsified New York business records to conceal crimes that hid damaging information from the voting public during the 2016 presidential election," Manhattan District Attorney Alvin Bragg said in a statement. "The trail of money and lies exposes a pattern that, the People allege, violates one of New York’s basic and fundamental business laws."