Is Trump running for president mostly to avoid prison?

It's impossible to know how genuinely worried Donald Trump may be about the prospect of going to jail for any of the criminal offences he has been charged with.

He claims he could be facing a combined 561 years in prison thanks to the "Left's witch hunts". That may be an exaggeration, but if he is convicted in any of the three court cases he faces, a jail sentence may well follow.

So whilst Mr Trump says almost nothing during his court appearances, he is voluble outside when he is appealing to the court of public opinion. Looking for a verdict that will come from tens of millions of voters, not a jury of 12. Delivered at the ballot box, not in a courtroom.

The lesser-known former congressman Will Hurd was booed off stage at a Republican dinner in Iowa last week when he said the only reason Mr Trump is running for the White House is to stay out of jail. But is he completely wrong?

The former president has already woven his election campaign and legal problems tightly together.

He uses the charges against him as a major plank of his campaign. In speeches he tells his supporters that he is being prosecuted because the establishment - or the "deep state"- fear him being re-elected as president.

He sends out fundraising emails that say: "If these illegal persecutions succeed, if they're allowed to set fire to the law, then it will not stop with me. Their grip will close even tighter around YOU."

And he has already used at least $40m (£31m) in campaign donations to pay his legal fees.

Mr Trump has made clear that no verdict or sentence will halt his campaign. That he will carry on running for president from behind bars if he has to.

And that if elected he will use the power of his office to either quash any ongoing prosecutions or pardon himself for any convictions.

But trying to escape his legal difficulties by running for president will soon become a scheduling nightmare.

Mr Trump has already announced a campaign event in New Hampshire next week, a long way from the court hearing that takes place in Florida two days later.

He doesn't have to appear on that date to hear the additional charges that have been filed against him in the case of the classified documents he took from the White House.

But when the trials get started, in New York in March, in Florida in May and in Washington at a date yet to be determined, he will be required to sit through the proceedings in person.

Even for someone with a private plane at his disposal that will make it hard to be hitting the campaign trail whilst on trial.

So far each indictment against Mr Trump has increased his poll ratings and tightened his grip on the Republican Party.

It may be a different story when we are in a general election and Mr Trump is running against Joe Biden rather than his rivals for the Republican nomination.

And when evidence against Mr Trump is being aired in court daily.

Yet it is once again Mr Trump who is defining the terms of the debate.

And making it all about him.

Who's listening to arguments about economic policy when the Trump trial cavalcade is in town?

You can hear more of Sarah's analysis by tuning into Americast, the BBC's US politics and culture podcast, on BBC Sounds or wherever you get your podcasts

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