Donald Trump's lawyer, Rudy Giuliani, called the idea of the president pardoning himself "unthinkable." But within a day of that brush-off, the much-disputed power of the U.S. president to absolve himself of a potential crime is precisely what's on Trump's mind.

Scholars studying fascism say the self-declared "law and order" president is now floating a trial balloon they say is reminiscent of authoritarian leaders.

In a tweet sent around 8:30 a.m. on Monday, Trump appeared to be testing public reaction to the prospect of him having the "absolute right" to self-pardon for potential charges of obstruction of justice related to the FBI investigation into Russian meddling in the 2016 election. (Not that he'd ever need to resort such measures, he noted.)

As has been stated by numerous legal scholars, I have the absolute right to PARDON myself, but why would I do that when I have done nothing wrong? In the meantime, the never ending Witch Hunt, led by 13 very Angry and Conflicted Democrats (& others) continues into the mid-terms! —@realDonaldTrump

"This is a president who has taken the unthinkable and made it thinkable," said conservative political analyst Charlie Sykes, author of How the Right Lost its Mind.

"Why go there? Unless you're floating it to see what would be considered acceptable in Congress and to the public."

Whether or not Trump really has the constitutional right to grant himself clemency is beside the point for some critics. That the president is publicly flexing these powers in the first place is more troubling for New York University professor Ruth Ben-Ghiat, a scholar on fascism and authoritarian leaders.

"It's in the tradition of the trial balloons he's been launching since his campaign, which warn the public and his GOP allies that he feels he's above the law," she said.

Trump's tweet followed Giuliani's comments over the weekend that the president couldn't be prosecuted, even "if he shot James Comey," the former FBI director who Trump fired amid the bureau's probe into Russian meddling in the 2016 election.

Rudy Giuliani, centre, an attorney for Trump, said it would be 'unthinkable' for the president to pardon himself. (Andrew Harnik/Associated Press)

Impeachment would be the only remedy to bring charges against the president, Giuliani argued.

"I lost sleep about this last night, which is rare for me," Ben-Ghiat said of Giuliani's remarks. The language echoed Trump's campaign boast in January 2016 that he "could stand in the middle of Fifth Avenue and shoot somebody without losing voters."

Political enemies of Russian President and former KGB agent Vladimir Putin often end up dead. Putin adopted a law in 2006 permitting extrajudicial killings abroad.

Ben-Ghiat compared the violent imagery about Comey to the chilling populist speeches Philippines President Rodrigo Duterte delivered during his campaign to wipe out crime by killing drug dealers. "If I become president, it would be bloody, because we'll order the killing of all criminals," Duterte said.

That's an extreme case, but Ben-Ghiat interprets Trump's self-pardons tweet as the president exploring the limits of his authority with his base.

"It's meant to introduce into public discourse unthinkable ideas, and to start working on the public to make those ideas acceptable."

People who study authoritarianism recognized message-hammering that has branded flimsy conspiracy theories — like "Spygate" and "Uranium One" — and repetition of the phrase "no collusion" to turn it into shorthand for deflecting allegations of wrongdoing in the Russia probe.

After a string of recent pardons over the past month, Trump is now discussing the concept of self-pardoning, though his Republican defenders, including Giuliani and Representative Kevin McCarthy, deny the president has any authoritarian streak.

A self-pardon won't happen, said McCarthy, who as majority leader holds the No. 2 job in the House of Representatives. He told reporters he views Trump's use of the pardon authority as aligning with the normal "checks and balances" of the executive branch.

Trump has lavished praise on Philippines President Rodrigo Duterte, who has demonstrated authoritarian tendencies. (Romeo Ranoco/Reuters)

Speaking to CNN on Monday night, Giuliani said Trump likely mentioned his ability to self-pardon to "illustrate and create the discussion of how complete the pardon power is."

He also commended Trump's pardons of former Arizona sheriff Joe Arpaio (convicted of criminal contempt for defying a court order to stop detaining suspected undocumented immigrants) and Scooter Libby (obstruction of justice and perjury) as "highly justifiable."

But for Trump to suggest he can pardon himself "is to suggest the president is above the law," said Yascha Mounk, who lectures on government at Harvard University and researches the rise of populism.

"I'm absolutely horrified by it," he said. "I step back, and even I see myself becoming numb to it all. And so I'm as horrified by how numb I've become by what the president says. We shouldn't be cavalier about the amount of political danger this portends."

Cas Mudde, a political scientist with the University of Georgia who focuses on populist movements in the U.S. and Europe, laid out a pattern the president seems to follow for introducing controversial ideas:

"Suggesting the possibility of something very controversial, saying he's not really going to do it, then waiting for the liberal outcry, the conservative rallying-around-the president, and the hoped normalization of the suggestion, just in case he will need it in the future," Mudde said.

During the presidential campaign, Trump proposed a "complete shutdown" of all Muslims entering the U.S. Once in office, he signed an executive order banning people from several Muslim-majority countries. It met liberal and legal challenges, was tweaked, and is now being enforced as the Supreme Court considers its merits.

Hungarian leader Viktor Orban has undermined democratic checks and balances, according to a specialist in populism and fascism. (Kacper Pempel/Reuteres)

In March 2016, Trump also proposed that women who receive abortions should face "some form of punishment," though he eventually backed off amid a political outcry from both sides of the aisle. Last January, Trump invoked a phrase reminiscent of Soviet dictator Joseph Stalin when he slammed the free press as "the enemy of the American people."

The media have become a normalized object of hate at his campaign events.

"The instinct there is, 'Look, I was elected, I should be able to do whatever I want, so what is it that would potentially constrain me from doing that? The courts, the media, other political parties,'" said Sheri Berman, a professor specializing in populism and fascism at Barnard College, Columbia University.

Strongmen like Russia's Putin, Turkey's Recep Erdogan and Hungary's Viktor Orban have been known to "bask in their ostensible electoral support" while undermining the democratic checks and balances of opposing parties, or the courts, Berman said.

Erdogan, for example, has cracked down on the freedom of the press and the independent judiciary, saying a 2016 ruling by the Constitutional Court to free two journalists charged with attempting to overthrow his government was "against the country and against its people."

To Berman, Trump suggesting he has the right to pardon himself "is perhaps the most egregious example of him saying he cannot be constrained by the legal system."

Special counsel Robert Mueller's investigation into Trump has spurred a number of Twitter tirades from the U.S. president. (Andrew Harnik/Associated Press/Leah Millis/Reuters)

"The whole reason we have an executive branch, a legislative branch and the courts is precisely to ensure that none of them go too far," she said. "If presidents are pardoning themselves, then what's the whole point of the separation of powers?"

Pressed by reporters on whether Trump feels he's above the law, White House Press Secretary Sarah Huckabee Sanders said Monday Trump "hasn't done anything wrong," before eventually saying "certainly no one is above the law."

Berman feels Republicans have been stretched by Trump's testing of his executive privilege, and "don't seem to have any breakpoints," though some conservatives like former New Jersey governor Chris Christie have warned Trump "will get impeached" if he goes that route.

For example, Texas senator John Cornyn reiterated "there's no evidence of collusion" against Trump, calling the talk of pardons "a distraction because I don't think it will happen."

Academics remain divided about the constitutionality of a presidential self-pardon.

In general, the president has broad authority to pardon federal crimes. But a 1974 Justice Department memo on the question of whether president Richard Nixon could pardon himself was met with a resounding no, on the grounds that "no one may be a judge in his own case."

Law professor Jonathan Turley argues Trump has the legal authority to pardon himself, though he warns it would be 'self-defeating,' because he would likely be impeached for it. ( Brennan Linsley/Associated Press)

It boils down to how one interprets silence in the constitution on the matter of self-pardons.

"The president is probably correct," says George Washington University constitutional legal scholar Jonathan Turley.

While the argument against "self-dealing" has been made, Turley's view is that past presidents have already engaged in using those powers for their benefit, including Trump's "open nepotism" for appointing his family members to White House staff, and president Bill Clinton pardoning his own half-brother, Roger, for a cocaine possession and drug-trafficking conviction.

Although Turley believes Trump can self-pardon, he says doing so would be impeachable and arguably an abuse of authority that legislators wouldn't stand for, especially if Democrats regain control of both chambers of Congress following upcoming midterm elections.

"If President Trump were to grant himself a self-pardon, it would be arguably the most ignoble moment in the history of the American presidency," Turley says. "But certainly, it would also be self-defeating."