According to today's opinion, Trump's contention that he doesn't have to face Summer Zervos' lawsuit while in office conflicts with the fundamental principle that the United States has a "government of laws and not of men."

In a lengthy decision of great significance, a New York appeals court has affirmed a decision that President Donald Trump must face a defamation lawsuit brought by season-five Apprentice contestant Summer Zervos.

The dispute arose after audio was published of Trump boasting to Access Hollywood's Billy Bush about grabbing women's genitals. As Trump was under fire for his comments, Zervos came forward to accuse him of kissing her twice in 2007 and attacking her in a hotel room. "I never met her at a hotel," responded Trump, who would also counter allegations from his accusers as "100 percent fabricated and made-up charges, pushed strongly by the media and the Clinton campaign."

Zervos alleged in her lawsuit that she was branded a liar.

That led to Trump arguing that the U.S. Constitution didn't allow this case to proceed right away thanks to the Supremacy Clause, which Trump's attorney, Marc Kasowitz, posited meant "that state governments, including their courts, refrain from interfering in the operations of the federal government."

"No one is above the law," ruled New York state judge Jennifer Schecter a year ago in a decision that allowed the suit to continue.

On Thursday, the First Appellate Division in New York affirmed that holding.

Appellate judge Dianne Renwick writes that the Supremacy Clause applies to federal laws, not federal officers.

"Defendant's reading of the Supremacy Clause — that it bars a state court from exercising jurisdiction over him because he is the 'ultimate repository of the Executive Branch's powers and is required by the Constitution to be always in function' — finds no support in the constitutional text or case law," states the opinion. "Defendant's interpretation conflicts with the fundamental principle that the United States has a 'government of laws and not of men.'"

The opinion (read in full here) also addresses Clinton v. Jones, a 1997 U.S. Supreme Court opinion, which determined that presidents aren't immune from civil actions in federal court.

"Congress has not passed any law immunizing the President from state court damages lawsuits since Clinton v Jones was decided," writes Renwick. "Therefore, because Clinton v Jones held that a federal court has jurisdiction over the kind of claim plaintiff now asserts and because there is no federal law limiting a state court from entertaining similar claims, it follows that state courts have concurrent jurisdiction with federal courts over actions against the President based on his purely unofficial acts."

Later, Renwick shrugs off Trump's concern that because the state court has the power to hold him in contempt should he not obey court orders that would constitute an impermissible exercise of authority over him. The judge says it's merely a "hypothetical concern" and that the issue is not what's presently before the appeals court.

Trump also attempted to defeat the lawsuit by invoking California's anti-SLAPP statute and arguing that Zervos had no likelihood of prevailing in a defamation claim over statements he characterizes as opinion or hyperbole.

"The use of the term 'liar' could be perceived in some cases as no more than rhetorical hyperbole that is a nonactionable personal opinion," acknowledges the appellate judge before rejecting the argument. Trump, she continues, "used the term [liar] in connection with his specific denial of factual allegations against him, which was necessarily a statement by him of his knowledge of the purported facts."

Nevertheless, it's the Supremacy Clause discussion that is the big ticket here, as no appellate court had previously determined whether the president of the United States must face state suits while in office. And given that Trump is facing other actions as well as the potential for criminal indictments in New York, the determination that he can't use his federal office to shield himself is undeniably consequential.

In a dissent, New York appellate judge Angela Mazzarelli comes to an alternative conclusion about the Supremacy Clause. She writes, "[S]ubjecting the President to a state trial court's jurisdiction imposes upon him a degree of control by the State of New York that interferes with his ability to carry out his constitutional duty of executing the laws of the United States."

Trump may continue to appeal the outcome up the New York Court of Appeals, the Second Circuit Court of Appeals and, ultimately, the U.S. Supreme Court. However, because the trial proceedings have not been paused during the pendency of the appeal, he'll likely have to give a deposition in the coming months as both sides pursue the truth of what happened a decade ago through discovery.