NEW YORK (AP) — Donald Trump isn't used to constraints.

The former president ignores and antagonizes anyone who tells him no. He built a business — and later political — brand as someone who says and does what he wants, largely without consequence. Even after losing the White House, Trump remains accustomed to deference, surrounded by people who greet him with nightly standing ovations at his clubs and cheer his most outrageous lies.

But Trump came face-to-face with a new reality Wednesday when he was called to the witness stand and fined $10,000 for violating a gag order prohibiting him from attacking court personnel in his New York civil fraud case. Trump denied he was referring to a senior law clerk when he told reporters in the courthouse hallway that someone "sitting alongside" Judge Arthur Engoron was "perhaps even much more partisan than he is."

Engoron wasn't having it.

"I find that the witness is not credible," he concluded before issuing the fine. Minutes later, Trump stormed out of the courtroom in an apparent fit of anger.

The $10,000 holds little financial consequence for a wealthy defendant who flew to his appearance aboard a private jet.

But the courtroom drama previews the tensions mounting between Trump's competing legal and political interests as he vies for the Republican presidential nomination while facing a litany of criminal and civil cases. And it underscores how efforts to hold Trump accountable are testing the legal system in unprecedented ways as judges struggle with how to rein in the former president's inflammatory rhetoric while balancing the free speech rights of a political candidate.

"It's really a new frontier for the legal system, and the legal system is really struggling with how to control this man who has no respect for the rule of law," said Jimmy Gurule, a Notre Dame law school professor.

The court system has never encountered this type of defendant. Trump is not only a former president, but also the leading candidate for the 2024 Republican presidential nomination. He has turned his legal fights into a centerpiece of his campaign while also painting himself as the victim of coordinated political persecution.

Lawyers typically tell criminal defendants to stay quiet, knowing prosecutors can use any utterance against them. But Trump has turned the camera-lined hallway outside the courtroom into his own personal campaign stage, holding impromptu press conferences multiple times a day as he enters and exits the room. He also broadcasts his grievances on his social media platform, where he regularly slams Engoron as "a Radical Left Democrat" controlled by New York Attorney General Letitia James "and her Thugs."

Gurule said courts are hamstrung in trying to punish Trump the way they would normal defendants because of his position and personal wealth. A $10,000 fine is unlikely to deter someone as rich as Trump. And while Engoron floated the possibility of holding Trump "in contempt of court, and possibly imprisoning him" for further violations, jailing an ex-president who is under Secret Service protection would present enormous logistical challenges, in addition to the grave political implications of putting a leading political candidate behind bars.

The absence of meaningful consequences raises questions about whether Trump's prominence has allowed him to exist under a "different standard of law" than other defendants, Gurule said.

Indeed, fines and the threat of jail haven't deterred Trump yet. Just days ago, he was fined $5,000 for violating the same gag order, which Engoron imposed after Trump targeted his principal law clerk on social media. While Trump immediately deleted the post, the court later learned that a copy remained posted on his campaign website, which his attorneys called an unintentional oversight.

But Trump, so far, has capitalized politically on his trials, plastering his mug shot on merchandise that has brought in millions of dollars and fundraising off every development. Trump fretted last week that his appearances in court weren't drawing as much media attention with the spotlight turned to the war in the Middle East and the House speakership debacle. But with the latest courtroom drama, he was once again making headlines, overshadowing his rivals and filling his campaign coffers.

"For some people, this is what they like about Trump — that he doesn't back down, he pushes against others and he is his own master. But in the world of the courts, the rules are different," said Laurie Levenson, a former federal prosecutor and professor at Loyola Law School.

While Trump's tactics may have political benefits, they could also help prosecutors argue the former president believes he's above the law.

"If he disregards orders of the court, then it may add to the argument that he was disregarding other laws as well," she said.

"By his actions, he's messaging that the laws don't apply to me. And that's problematic because a good prosecutor — and I think Jack Smith is a good prosecutor — can use that at the right time against him," Levenson said, referring to the special prosecutor overseeing the federal cases against Trump.

Indeed, things are likely to get much more complicated for Trump in the coming months as his four criminal trials get underway. While the New York fraud case is a civil trial at which Trump has appeared voluntarily, he is likely to face far tougher restrictions and harsher punishments in his criminal cases.

In 2017, a federal judge in Brooklyn revoked the bail of pharmaceutical company CEO Martin Shkreli, who had been convicted of fraud, and sent him to jail after he went on social media and offered a $5,000 bounty to anyone who could get him a strand of Democrat Hillary Clinton's hair. Shkreli's lawyers said he was just joking, but the judge called that offer "a solicitation of an assault."

More recently, a federal judge in Manhattan revoked the bail of former cryptocurrency mogul Sam Bankman-Fried while he awaited trial on fraud charges after he gave journalists copies of the private writings of his former girlfriend, who was set to testify against him at a trial. The judge ruled that amounted to witness tampering.

Trump has so far seemed to abide by a separate gag order imposed by the judge overseeing his 2020 election interference criminal case in Washington. Trump has decried the order, which barred him from making public statements targeting prosecutors, court staff and potential witnesses, as unconstitutional and is appealing. But he waited until it was temporarily lifted Friday to resume his public attacks against Smith and label those who have made cooperation deals with prosecutors "weaklings and cowards."

Prosecutors asked late Wednesday for the gag order to be reinstated, citing recent social media posts about Trump's former chief of staff that they said represented an attempt to influence and intimidate him.

Trump has also avoided inflammatory remarks against Judge Aileen Cannon, who is overseeing the case into his alleged hoarding of classified documents at his Mar-a-Lago club, and whom he appointed.

In a typical court proceeding, a judge would likely be more concerned about whether a defendant has blatantly broken court rules, like trying to speak to jurors or threatening witnesses, than stray comments made outside of court about feeling like court personnel are biased. But Trump has an unparalleled megaphone, making his message potentially more dangerous at a time when judges are increasingly under threat.

The judge in Trump's hush-money criminal case, Juan Manuel Merchan, received dozens of death threats around the time of Trump's arraignment in April after the former president lashed out at him on social media. New York court officials have beefed up security for judges and court personnel involved in Trump matters in the wake of the threats.

"In the current overheated climate, incendiary untruths can, and in some cases already have, led to serious physical harm, and worse," Engoron said upon fining Trump on Friday.

___ Tucker reported from Washington and Durkin Richer from Boston. Associated Press writers Michael R. Sisak, Michelle L. Price, Jake Offenhartz and Jennifer Peltz contributed to this report.