JOHN YANG: Democratic Party officials will now have to negotiate state election laws.

And they're just six weeks away from the first mail-in ballots being sent out to voters in North Carolina.

Rick Hasen teaches at UCLA law school and is an expert on election law.

Rick, how hard or easy isn't going to be for Democratic Parties in the states across the country to change the balance?

RICK HASEN, UCLA School of Law: Well, they don't need to change anything at this point.

Because remember, Joe Biden was never the nominee officially of the Democratic Party.

He was the presumptive nominee, his name was going to be submitted either after this virtual roll call that was maybe going to take place in early August or at the convention.

So really, the fact that Joe Biden is dropping out now is not the issue.

The issue is one more of timing in terms of when the information from the party is going to be transmitted to the various state officials.

I think that it should go in almost every place very smoothly.

And there should not be an issue based on the fact that it's going to be a different nominee other than Joe Biden.

JOHN YANG: Now, before the President dropped out this morning, House Speaker Mike Johnson was out saying that he was going to expect legal challenges from Republican parties across the country to wall this.

How -- is there grounds -- are their grounds for a legal challenge?

And could that how long could that fight go on?

RICK HASEN: Well, I don't think that the legal challenges would be likely to be successful.

I think they'd be very unlikely to be successful.

Ohio, for example, had an early ballot deadline.

They changed the deadline to later.

But they the later -- the change doesn't go into effect technically until September 1st, but state officials have said, we're going to stick with the new deadline.

And so Democrats should be fine to put an anomaly after that convention.

So someone could try to challenge that.

The courts have been very protective of the rights of major party candidates to be on the ballot.

There are a few other states where technical issues could be raised like Washington State, I think these things are very unlikely to succeed.

And it's just kind of more smoke that's being thrown up to try to, you know, it was tried to keep Biden in the race and now to try to claim that Democrats are doing something illegitimate.

JOHN YANG: In your experience and your knowledge of the history of all this.

Has there ever been a presidential candidate dropping out this late in the campaign?

RICK HASEN: This is very late.

And remember the Democrats have a very late convention so everything is later I think maybe that was because of the Olympics were taking place between the two conventions.

It's very late.

But you know, lots of other countries run entire elections in the period that we would have between Labor Day and our election day.

So, you know, certainly, there's enough time to ramp up campaigns.

And I think that's what we're going to see.

JOHN YANG: Yeah, we've been reminded of those short campaigns recently, in Britain and in France.

What happens to the money that the Biden Harris campaign has raised?

RICK HASEN: It's going to depend on if Harris is the nominee or not.

Harris is not the nominee then Biden would have to either give the money away to the Democratic Party or two -- he could set up a Super PAC potentially, he could have his own PAC that could support a candidate, those things would be not as good as if Harris took over.

Most election lawyers think that of Harris takes over, she can just keep using the funds.

There are some people who claim that she wouldn't be able to do that, at least not yet.

And so it's possible there will be a challenge.

But usually campaign finance challenges come years later, we're still getting some resolution of things that happened in 2016, when it comes to campaign finance.

So I think if it's Harris, she's very likely to be able to take over the use of that money.

JOHN YANG: Now the process of choosing the next nominee, some Republicans are already criticizing it, saying that it's anointing Vice President Harris that it's anti small D democratic, taking the decision away from the voters.

What do you make of that?

RICK HASEN: Well, remember that the years ago, the parties didn't have a such a democratic process, really, the democracy comes mostly when it's the choice between the Democrat and the Republican.

It's since the late 1960s.

The process has been democratized.

But here you don't have the party leaders overcoming the will of someone who still wants to run for office, the person who was in the lead has said I'm stepping back.

And so you need to have some process.

And if anything, if it is Harris, remember, she was on the ticket with Biden, so she was getting those votes from the voters with Biden all along the way.

JOHN YANG: Are there any say that changing the balance or the ballots won't have to be changed that much, is not much of a challenge or a problem?

Are there other legal hurdles you can foresee in all of this?

RICK HASEN: Well, so what's going to have to happen is they're going to have to have their ticket, right.

So I think you might still see the roll call, virtual roll call take place so that the Democrats lock this up by early August.

That way any of those long shot legal challenges would be would be gone.

And I think it would be smooth sailing from the point of view of election law.

And that will really be about the politics of the whole situation.

JOHN YANG: Election law expert Rick Hasen of UCLA law school, thank you very much.

RICK HASEN: Thank you.