A single post can shift the entire political landscape, and today, Donald Trump did exactly that. His latest tweet has reignited speculation, debate, and a question that once felt unthinkable: what if a U.S. president were actually arrested?What would happen if he was arrested? How would his supporters react? And could he still run for president?If Donald Trump is arrested, you’re sure to see protests and counter-protests. Both have already started after Donald Trump announced on Truth Social that he wanted his supporters to protest and “take our nation back.”And If past high-profile cases are any indication, Trump would likely be processed somewhere in the district attorney’s office.This would involve having his mugshot taken and getting fingerprinted. Then, Trump would have to sit in a holding area or a cell to await his appearance before a judge. While we can’t predict the outcome of this case, most experts agree that, if he’s found guilty it’s likely Trump would only have to pay a fine. This seems more probable than a possible prison sentence of 4 years.Some people fear that, at any point in this process, Donald Trump’s supporters might cause another incident like the one that occurred on January 6, 2021 at the U.S. Capitol. While it is possible that Trump will rally his supporters to protest on his behalf, it’s likely that law enforcement and officials will be braced to react and, ideally, would be able to prevent another incident.But let’s say that, hypothetically, Donald Trump is found guilty of a crime. Could he still continue his campaign to be reelected as president of the United States?Well, yes. Nothing in United States law prevents a candidate from running if they’ve been convicted of a crime. Although, it would likely make his campaign more difficult. But if he did manage to win, even if he were sentenced to jail time, he could serve part of his presidential term behind bars.It’s hard to say with any certainty how this potential arrest might go down since no U.S. president has ever been prosecuted. And that includes Richard Nixon.It’s not impossible that our growing political divide could spiral out of control and that some extremist figures could advocate for civil war. Thankfully, this is unlikely to happen. Civil wars are rare, and almost never happen in wealthy, democratic countries.What’s certain is that news coverage of this case would be around the clock, and the political divide we’re experiencing would become much larger. And you’re sure to hear much more about it in the coming days.Arresting a former president would be a huge event, but what would happen if someone like, Vladimir Putin were to die suddenly? Well that’s a story for another What If.