AMNA NAWAZ: Former President Donald Trump's return to the White House upends the many criminal investigations and convictions he's faced over the last four years.

William Brangham is here now with me to explain what could happen next.

William, good to see you.

WILLIAM BRANGHAM: Hi, Amna.

AMNA NAWAZ: So, Mr. Trump is now president-elect.

He's no longer a candidate, no longer a private citizen.

He will assume office in just two months.

How does all of that change the legal landscape for him?

WILLIAM BRANGHAM: It changes absolutely everything.

I mean, there are four major cases facing the former president, and in one way or another, each of those cases is going to be fundamentally different.

Some of them are going to go away, some of them will be severely constrained, but it is safe to say that the legal jeopardy facing Donald Trump today is completely different than it was two days ago.

AMNA NAWAZ: How is that possible?

I mean, there is this idea that no one is above the law, so how does becoming president-elect so dramatically change the legal landscape?

WILLIAM BRANGHAM: Let's talk about just the first two federal cases to explain this point.

Those are the cases that are under the Department of Justice, specifically under special counsel Jack Smith.

That is the January 6 election interference case that accuses the former president of lying about the election, orchestrating this vast scheme to subvert Biden's win back then.

The secondary case is the Mar-a-Lago classified documents case.

Both of those cases are in different stages.

I mean, the January 6 case was basically being slimmed down because the Supreme Court granted Donald Trump immunity.

That case was slowly moving forward.

The Mar-a-Lago case had been dismissed by the judge overseeing that, Aileen Cannon, because she said Jack Smith had been unconstitutionally appointed.

So both of those cases were already in a difficult position now, but Donald Trump moves into the White House.

He and his Justice Department now assumes authority over those cases.

His new attorney general simply dismisses Jack Smith and those cases vanish.

AMNA NAWAZ: Right.

WILLIAM BRANGHAM: Even if they would have gone forward though, there is a longstanding Department of Justice policy that says you don't prosecute sitting president.

You just don't -- president.

You just don't do that.

The idea being the president has other things to do.

You don't have to tangle him up in a case that he has to defend.

So those cases would likely have gone away.

Jack Smith is now, we believe, winding down those cases.

He will likely issue some report.

Whether we see that publicly or not, we don't know.

AMNA NAWAZ: But those are federal cases you were just talking about under the Department of Justice.

There are also two state cases at play here, right, including the one down in Georgia, election interference being brought by the district attorney there, Fani Willis.

What happens there?

WILLIAM BRANGHAM: The key distinction you made there is state versus federal.

Donald Trump would not have authority to dismiss the Georgia election interference case.

That is the one being brought by Fani Willis, the district attorney down there.

That case similarly was -- it's currently being appealed.

Trump and his 14 co-defendants on that case are saying you should remove the DA on this case because of her inappropriate relationship with one of her lawyers.

That was, again, slowly moving along, but it would suffer the same issue as the federal cases, in that a state prosecutor is not supposed to be charging and prosecuting a sitting president.

So that case also would have gone away.

It's expected that she would have to honor that as well.

AMNA NAWAZ: There's also a case in which she's already been convicted, right, the 34 felony convictions for the hush money case in New York.

What happens with those convictions?

WILLIAM BRANGHAM: That's right.

Judge Juan Merchan, who is overseeing this - - this is the Stormy Daniels hush money case that Trump was convicted of falsifying business records to cover up that extramarital affair.

Sentencing for that, those 34 charges was supposed to happen in three weeks.

Trump's lawyers will certainly appeal saying, look, now that the president is going to become the new -- the former president is going to become the new president, we need to postpone the sentencing on that.

And that has happened already twice before.

If it doesn't, the pressure on Judge Merchan to not put Donald Trump in prison, given that he's about to become the president, is going to be enormous.

Yes, these are 34 felonies, but these are nonviolent felonies.

He doesn't have a previous record.

Several members of Congress have already said this case and all the others ought to be dismissed now.

So it's hard to know what's going to happen with that one.

AMNA NAWAZ: William, there are some who've wondered if there's anything that can be done in the two months the President Biden has left in office to fast-track remaining cases.

Is there?

WILLIAM BRANGHAM: Short answer is no.

Two months is simply not enough time for any of these cases to finish their hearings, to start an actual court case and to be heard and wrapped up before Donald Trump gets back to the White House.

AMNA NAWAZ: All right, William Brangham, thank you so much.

WILLIAM BRANGHAM: You're welcome.