The president already is the subject of investigations by New York officials, and he may be implicated by federal authorities as well. As a private citizen, he would no longer enjoy de facto immunity.

Transcript

AILSA CHANG, HOST:

President Trump is no stranger to the courts. He's famous for his litigious streak. But when Trump leaves the White House on January 20, he could face a legal reckoning. NPR justice correspondent Ryan Lucas has the story.

RYAN LUCAS, BYLINE: Of all the perks of being president, Donald Trump may soon miss most the legal protection that it affords. For the past four years, Trump has benefited from the de facto immunity from prosecution that all presidents enjoy while in power. But that mantle passes to Joe Biden on January 20, when he takes office, leaving Trump exposed to significant legal risk, says Danya Perry, a former state and federal prosecutor in New York.

DANYA PERRY: Clearly, the president enjoyed immunity while he was in office. And it's possible, as a matter of law, that he could be indicted on January 21.

LUCAS: Perry says from a legal standpoint, the most developed case that could ensnare Trump is out of the southern district of New York. It stems from the federal prosecution against Michael Cohen, Trump's onetime personal attorney and fixer. Cohen pleaded guilty to a range of crimes, including arranging illegal hush money payments to keep women silent during the 2016 campaign about alleged affairs with Trump. Cohen has said he acted at Trump's direction, and prosecutors referred to the president in court papers as individual one.

PERRY: Ordinarily, had the target not been a sitting president with immunity, I think individual one, as he is called, very likely would have been prosecuted along with his aider and abetter, Michael Cohen.

LUCAS: But there could be significant complications to pursuing such a case. For one, prosecuting a former president is politically fraught. The decision on whether to do so at the federal level will fall to the new administration. President-elect Joe Biden has said he'd leave the decision to the Justice Department but also said this.

(SOUNDBITE OF ARCHIVED RECORDING)

JOE BIDEN: I think it is a very, very unusual thing and probably not very - how can I say it? - good for democracy to be talking about prosecuting former presidents.

LUCAS: There's also the possibility that Trump could pardon himself before leaving office, although that could be challenged. What is clear about Trump's pardon power, however, is that it does not extend to crimes at the state level. And for Trump, that could be problematic. That's because Manhattan district attorney Cyrus Vance has an open investigation into Trump and his businesses. The exact contours of Vance's probe are not known, but court papers suggest he's investigating possible insurance or financial fraud.

KIM WEHLE: That looks like it's the most likely place where he could have some criminal liability around taxes, for example.

LUCAS: That's Kim Wehle, a professor at the University of Baltimore School of Law and a former federal prosecutor. The case has been tied up for months as Trump fights a grand jury subpoena to his personal accounting firm for eight years of his tax returns and financial records. Trump's lawyers argue the subpoena is too broad and is politically motivated. Vance has rejected those claims and patiently forged ahead. And there's every expectation the investigation will accelerate once Trump's out of office. Again, Wehle.

WEHLE: It's hard to imagine that Cyrus Vance would have put this kind of effort into investigating Donald Trump while he was president if he was just going to drop that investigation and anything that could come out of that when he is a private citizen like anyone else.

LUCAS: If anything, Wehle says, Vance will be freer to pursue the case once Trump is out of office because he will no longer be protected by the cloak of presidential immunity. There is also other legal trouble brewing in New York. State Attorney General Letitia James has an active civil investigation that is looking into whether the Trump organization improperly inflated the value of its assets for loan or insurance purposes and then deflated the value for tax purposes. And then there are the defamation lawsuits filed against Trump by women who say he sexually assaulted them. In all, it adds up to a legally perilous and potentially expensive post-presidency.

Ryan Lucas, NPR News, Washington. Transcript provided by NPR, Copyright NPR.