Editor’s Note: Paul Callan is a CNN legal analyst, a former New York homicide prosecutor and counsel to the New York law firm of Edelman & Edelman PC, focusing on wrongful conviction and civil rights cases. Follow him on Twitter @paulcallan. The opinions expressed in this commentary are his own. View more opinion on CNN.

CNN  — 

President Donald Trump talks a lot about staying in office longer than the two-term, eight-year limit allowed by the Constitution. People may assume he’s joking – just needling his enemies. He couldn’t possibly be serious, could he?

Maybe we shouldn’t be so quick to dismiss the possibility that he sometimes means what he so often says. With Trump you don’t know. At the moment, critics are accusing the President of hedging his bets in the upcoming election by starving the US Postal Service of funding as the agency faces the monstrous task of delivering a record number of mail-in ballots during the pandemic.

And as November draws closer, President Trump has indeed adopted a more ominous tone about the election. In speeches and interviews he complains endlessly about “voter fraud” and warns that Democrats will use millions of fraudulent mail-in ballots to steal his second term. He refuses to say he will accept the election results.

Maybe he is just trying to agitate his opponents. What if he isn’t? How would America deal with the unprecedented refusal of a defeated president refusing to give up power?

The peaceful and voluntary presidential transition is one of the enduring glories of American democracy. The precedent was established by George Washington, who refused to run for a third term despite pressure to do so in 1797.

No American president has ever sought to retain the presidency after losing an election. There have been many close elections in presidential history such as the Kennedy-Nixon race in 1960 and the Bush-Gore contest in 2000.

In the 1960 race Nixon supporters groused that voter fraud they alleged was orchestrated by Lyndon Johnson supporters in Texas and Mayor Daley’s Democratic machine in Chicago tilted a very close race to John F. Kennedy. Despite these suspicions, Nixon swiftly dropped any fraud challenge and graciously accepted Kennedy’s ascension to the presidency.

Al Gore did the same thing when the Supreme Court ruled George W. Bush the winner by a razor thin majority of contested Florida votes in the 2000 election.

Both losing candidates earned the respect of the nation for what appeared to be a selfless decision to unite behind a new president rather than demand a prolonged voter fraud investigation.

Trump, though, delights in trampling tradition as he plots a different course.

He began his quest for the presidency by falsely claiming that then-candidate Barack Obama, was not qualified to serve as president because he was not born in the United States. The claim was conclusively disproven when Obama produced his certified long form Hawaiian birth certificate, and Trump himself, in September 2016, finally admitted “President Barack Obama was born in the United States.”

Still, he is so fond of the theme that last week he seemed to endorse a slight variation on it with respect to Kamala Harris’ right to run for vice president on the Biden ticket. Trump asserts, falsely, that she is “possibly” unqualified to run because her immigrant parents were not US citizens on the date of Harris’ birth in Oakland, California.

It is no wonder, therefore, that some opponents worry that the highly unpredictable and controversial Donald Trump might just try to hold on to power even if he loses.

Were he to attempt such a maneuver, however, history suggests it would end with his personal humiliation, disgrace, and possible imprisonment on criminal charges. In 1807 former Vice President Aaron Burr was tried for treasonous acts against the United States, establishing the precedent that even holders of the nation’s highest elected positions can be charged with criminal offenses.

Though Burr was acquitted, it seems clear that an attempt to illegally seize and retain presidential power would violate a variety of criminal conspiracy laws.

The US Constitution specifies in Article 2, Section 1 that after his election, the President will hold office for a “term of four years…” The clear meaning of this provision is that at the conclusion of those four years, unless reelected to one additional four-year term permitted by the 22nd Amendment, the President shall immediately forfeit all executive powers and become an ordinary citizen.

If the President refused to vacate the Oval Office at the completion of his first four-year term, severe consequences would follow. He would probably be reminded of this during a visit from the leaders of both parties in the Senate and House of Representatives. A similar congregation of politicians persuaded Nixon to resign during the Watergate scandal.

To beef things up in this case (which, were it to happen, would be much more serious than Nixon’s predicament), such a group might be joined by members of the Joint Chiefs of Staff to make it clear that the military will also stand with the Constitution rather than a rogue president.

In this speculative scenario, should Trump persist in an attempt to retain presidential power, it would likely be viewed as a criminally treasonous conspiracy under the Constitution. Treason can result in lengthy imprisonment or even the death penalty under US law. Trump undoubtedly knows this because he regularly accuses his opponents of treason.

He also loves lawsuits so we might certainly expect him to file a lawsuit seeking to overturn the election results on basis of “fraud” if he loses.

But he would likely be upset to learn that if such a lawsuit delayed the inauguration of a new president past the constitutionally scheduled date of January 20, 2021, the laws of presidential succession would bestow the presidency on his nemesis, House Speaker Nancy Pelosi, pending certification of a new president by the Supreme Court and the Congress.

While serving as interim president, Pelosi would undoubtedly order Trump’s arrest and confinement in the Tower, the Trump Tower, under house arrest to await his treason trial.

Under such circumstances, despite the President’s bluster about keeping his options open concerning presidential election fraud, Trump will pack his bags and head for his new low-tax Florida home if he loses the election.

In the world’s oldest continuous democracy even a “stable genius” can’t outsmart the US Constitution.

Correction: An earlier version of this piece incorrectly stated the year George Washington's second term ended. It was 1797.