Donald Trump's criminal trial in New York is turning Manhattan into the Republican leader's new campaign headquarters. Proof of this is the attendance of the former president's allies and potential vice presidential candidates in the courts.

Because his presence at the trial is mandatory, Trump must focus on New York and, particularly, the Manhattan courts.

This Monday, for example, the presence of Senator JD Vance (R-OH) was notable. During the day, he played a leading role by questioning the testimony and integrity of Michael Cohen, the prosecutor's star witness.

"Michael Cohen is the prosecution's star witness. This guy is a convicted felon (…) Does any reasonable, sensible person believe anything that Michael Cohen says?" said the senator outside the court. "Every single person involved in this prosecution is practically a Democratic political operative (...) What's going on inside that courtroom is a threat to American democracy."

JD Vance is, precisely, one of the main candidates to be former President Trump's running mate along with his colleagues Marco Rubio (R-FL), Tim Scott (R-SC) and Doug Burgum, governor of North Dakota.

However, Vance is not the only high-profile politician who has appeared in court to support the former president.

Last week, Senator Rick Scott (R-FL) accompanied Trump to court, prompting various journalists' reactions. Some of them claimed that the courthouse in Manhattan would become the epicenter of potential Republican vice presidential candidates and Trump's most prominent allies during the coming weeks of the trial.

"It's very clear ever since Sen. Rick Scott came. I just thought that day, 'Ok, the parade's beginning now.' This will be the vice presidential nominee audition bench," said MSNBC host Lawrence O'Donnell.

Along those lines, former presidential candidate Vivek Ramaswamy confirmed his presence in court for Tuesday, a key date for Trump's campaign.

"The best proof that the Trump trial is a sham: if DJT had done the exact *opposite* of the alleged crime, they'd still be prosecuting him & have an even stronger case," the billionaire former biotech executive said in a statement sent to Fox News Digital.

Ramaswamy's presence this Tuesday is no coincidence.

According to ABC News, for the day, Senators Tim Scott and Marco Rubio and Republican Governors Doug Burgum and Kristi Noem, all potential vice presidential candidates, will join Trump at a high-cost fundraiser in Manhattan organized by billionaire financier Howard Lutnick.

Other politicians or allies who have joined Trump in Manhattan in recent weeks included Alabama Sen. Tommy Tuberville, New York Republican Rep. Nicole Malliotakis, and Alabama's Republican Attorney General Steve Marshall and Iowa's Attorney General Brenna Bird.

For the rest of the week, the former president has several fundraising events planned.

On Wednesday, the day Trump will rest from the trial in Manhattan, Senator Vance will again join Trump at a fundraising lunch in Cincinnati, Ohio.

Also, on Friday, when the former president will attend his son Barron Trump's graduation, the Republican leader will headline a fundraiser in Minnesota for the state Republican Party's Lincoln Reagan Dinner.