“The standard language may not work here, when you have thousands of Americans who could be witnesses and he continues to have daily contact with people who may be involved,” said Laurie Levenson, a law professor at Loyola Law School of Loyola Marymount University in Los Angeles. “Everything is more complicated in this case because of who the defendant is, what he has done and that he wants to be president again.”

A test for Trump may come as early as Friday. He is attending the Alabama Republican Party’s annual Summer Dinner. On Saturday he will deliver the keynote speech at the South Carolina GOP’s 56th Annual Silver Elephant Gala.

As his campaign unfolds, the potential witness pool in his latest case is very broad. The congressional hearings on the Jan. 6, 2021, Capitol riot could offer some insight — those interviews spanned more than 1,000 people, and included some of Trump’s closest advisers and family members, including his daughter Ivanka and his son Donald Trump Jr.

So it’s possible he may already be talking about the case in front of witnesses.

Even as he traveled to Washington Thursday for his arraignment, Trump was accompanied by top aides including Jason Miller, a communications staffer who had been featured heavily in the Jan. 6 congressional hearings, and Boris Epshteyn, a longtime adviser who was part of the efforts to overturn the election results by organizing fake electors. The complications reflect the reality that Trump’s campaign and his legal issues are now intertwined.

“The legal messaging is the political messaging and the political messaging is the legal messaging,” Trump campaign spokesman Steven Cheung said before the latest indictment. “It’s part of what we’re running on. Trump has made the legal issues a big focus of his campaign and from our standpoint, it’s messaging that works.”

Trump makes reference to the 2020 election in almost every speech he gives, telling his supporters that he ran twice and won twice as he vows to do it again. Trump’s speeches also often include extensive discussion of the cases he faces as he tries the cast the investigations as part of a politicized effort to damage his candidacy.

And many close advisers are potential witnesses. His 2024 campaign includes some, like Miller, who worked for his 2020 effort, as well as some new leaders who were not involved in his efforts to overturn the election.

The issue has come up before, after Trump was charged by federal prosecutors with illegally hoarding classified records at his Florida Mar-a-Lago estate and rejecting government demands to give them back.

In that case, there was a back-and-forth between the judge and Trump lawyers over whether he could speak to his co-defendant, valet Walt Nauta. Trump’s attorney Todd Blanche noted that Nauta and potential witnesses are people with whom Trump interacts daily, whether at his Mar-a-Lago resort in Florida or his other clubs.

The judge said he could speak with Nauta, just not about the case. Nauta was with Trump again in Washington on Thursday, holding an umbrella as the former president spoke to reporters before he boarded a plane back to Bedminster, New Jersey.

The former president and current Republican front-runner said on the tarmac that the latest case was “persecution” of a political opponent by President Joe Biden.

During his arraignment in Washington, where he pleaded not guilty to four counts, including conspiracy to defraud the United States, he agreed not to talk about the case with any witnesses without lawyers present, and not to attempt to influence any potential jurors or tamper with witnesses.

U.S. Magistrate Judge Moxila Upadhyaya told him that if he failed to comply with any conditions of his release, a warrant might be issued for his arrest. A formal witness list is usually presented closer to trial, though prosecutors often signal candidates earlier in the process.

The former president is not known to hold back or refrain from talking about off-limits subjects. He’s also been accused of defying court orders before, and he’s already been reprimanded by one judge overseeing a hush-money prosecution to refrain from comments that were “likely to incite violence or civil unrest.”

Georgia prosecutors have also been probing Trump and his allies for their efforts to overturn his election loss in that state.