Marc Kasowitz, a lawyer for President Trump, enters New York State Supreme Court on Dec. 5. He is arguing that the president should be immune from a state defamation lawsuit filed by a former contestant on his reality TV show, "The Apprentice." (Kathy Willens/AP)

The scene playing out in a New York court is the first time since President Bill Clinton was in office that allegations about a president's sexual conduct have been entangled in constitutional arguments.

Twenty years after Clinton fought accusations in a federal lawsuit brought by an Arkansas state employee, President Trump faces a state lawsuit that could open him to a similar predicament. The defamation suit brought by a female accuser could force scrutiny of Trump's personal life and even make him take the stand. Now, his longtime lawyer hopes to quash the suit — by putting a new spin on the Supreme Court ruling that allowed the case against Clinton to proceed.

Marc Kasowitz has homed in on a single footnote in the Clinton case that highlights what he calls a key difference: Paula Jones brought her harassment suit against Clinton in federal court; Summer Zervos, a former contestant on Trump's reality show, "The Apprentice," is suing Trump in a state court.

And state courts, Kasowitz argues, have no authority over a sitting president. What's more, the demands of fact-finding, depositions and court appearances are too time-consuming for the country's commander in chief.

"Only a federal court, with co-equal power to the president, has the authority to hear such a case," Kasowitz said earlier this month, revealing a strategy that legal scholars say has far-reaching implications.

"He's Trump's lawyer," said J. Maria Glover, a professor at Georgetown University Law Center, noting the scope of Kasowitz's contention. "He is making a sweeping argument for presidential power, which would preclude all future suits against Trump and all future sitting presidents in state courts."

[Trump could face a reckoning in case brought by female accuser]

Zervos, one of a number of women who have accused Trump of sexual misconduct, sat watching in the courtroom as Kasowitz and her attorney presented oral arguments in early December. The president's position "is unique," Kasowitz said. "Once the president is haled into court, there are innumerable obligations that flow from that," he said.

Mariann Meier Wang, who is Zervos's co-counsel with women's rights lawyer Gloria Allred, emphasized that they would work around Trump's schedule.

"He's a human being who does not do his job 24 hours a day, seven days a week," she said. "We can certainly ensure we take depositions down at Mar-a-Lago in between his playing golf," she added, referring to Trump's estate in Palm Beach, Fla.

Kasowitz, 65, is known as a street fighter in high-end financial litigation and has represented Trump for more than 15 years, through fallout from divorce, bankruptcy and allegations of fraud.

In 2016, he defended Trump, then a candidate, when he faced sexual misconduct allegations, and demanded a retraction when the New York Times published a report in which two women accused Trump of touching them inappropriately.

[A Trump libel suit against the Times? Don’t count on it]

In 2006, he brought a libel suit on Trump's behalf against biographer Timothy O'Brien, alleging that O'Brien's book underestimated Trump's net worth. A New Jersey judge dismissed the lawsuit.

Kasowitz Benson Torres, the New York-based firm he co-founded in 1993, now has Washington connections. Former senator Joseph I. Lieberman (I-Conn.) is a senior counsel, and David Friedman, Trump's U.S. ambassador to Israel, was a partner. Kasowitz served briefly as Trump's attorney in the investigations of Russian meddling in the 2016 presidential campaign.

The Zervos defamation case puts Kasowitz back in a familiar setting.

[President Trump and accusations of sexual misconduct: The complete list]

Kasowitz declined to comment for this report or to discuss his hourly fee, which in other instances has been reported as $1,500. But his court filings and oral arguments suggest an ambitious strategy.

The hearing also provided insight into Kasowitz's plans to pursue the fight if the New York judge allows Zervos to proceed.

Kasowitz is setting up for battle, Glover said. "Ultimately," she said, "the Supreme Court could weigh in on the constitutional question if it gets through New York's highest court."

Zervos is suing Trump not for sexual misconduct she alleges occurred during a 2007 encounter at his Beverly Hills Hotel bungalow but for comments he made during the campaign, when he called his female accusers liars.

Kasowitz argues that Trump's verbal attacks on the women were "part of the expected fiery rhetoric, hyperbole and opinion that is squarely protected by the First Amendment," and that Trump is immune from civil suits filed in state courts.

Presidential immunity has been the focus of two Supreme Court cases in the past 40 years. In 1982, the court ruled in Nixon v. Fitzgerald that the president's official acts were immune from liability. Fifteen years later, when Jones sued Clinton, the court addressed whether a sitting president was also shielded from civil lawsuits that were unrelated to official duties. In allowing Jones's suit to proceed, the court established the principle that nobody, not even a sitting president, is above the law.

The Clinton case was brought before the federal judiciary, which is of equivalent rank to the government's executive branch.

"There was a balancing," Kasowitz told New York Supreme Court Justice Jennifer Schecter in court, holding out his hands like the scales of justice.

What's more, a single footnote in the 1997 case left open a different interpretation.

"Because the claim of immunity is asserted in a federal court," U.S. Supreme Court Justice John Paul Stevens wrote for the court, ". . . it is not necessary to consider or decide whether a comparable claim might succeed in a state tribunal."

"The footnote leaves the question open, correct?" Schecter said.

"Even raising the question provides good guidance" for the court, Kasowitz said.

Trump's defense has been met with criticism.

"It's reasonable to raise the issue, since the Supreme Court noted it hadn't decided," said Elizabeth Samuels, a professor at the University of Baltimore School of Law. "You should pick all the arrows in your quiver," she said.

"Originally, there were no federal courts," said C.J. Peters, dean of the University of Akron School of Law. "So a constitutional argument that state courts have less power to enforce state law than federal courts seems counterintuitive, to say the least."

Three legal scholars who filed an amicus brief 20 years ago in Clinton v. Jones have done so again, asserting that "there is no reason to assume that suits in state court threaten to burden Presidents any more than suits brought in federal court."

The idea that a president might be incapacitated by litigation has won little sympathy in the past.

"In the more than 200-year history of the Republic, only three sitting presidents have been subjected to suits for their private actions," Stevens wrote in 1997. "If the past is any indicator, it seems unlikely that a deluge of such litigation will ever engulf the presidency."

If there is one certainty, it is that a pitched battle lies ahead, legal scholars say. Either side is likely to appeal Schecter's ruling.

"That can be a long process," said Naomi Mezey, a professor at Georgetown University Law Center, which could end up meeting one of Kasowitz's goals: delaying a trial until Trump leaves office.

The possibility of Zervos's case reaching the Supreme Court introduces another level of uncertainty.

"It's often hard to explain what great leeway the justices have," Samuels said, and that is one reason, she said, that the president's Supreme Court picks are so important.

"They could distinguish between suits brought in federal or state court, or even overrule or modify Clinton v. Jones," she said.

First, though, Schecter must rule, and she is weighing novel arguments. As she noted in court, she would enter uncharted territory if she were to dismiss the case, as Kasowitz proposed she should, on the grounds that a state court lacked authority over the president.

"This would be the first," the judge said.

"This would be the first," Trump's lawyer agreed.