(Jonathan Drake/Reuters)

President-elect Donald Trump tweeted Sunday, without evidence, that he would have won the popular vote if "millions" hadn't voted illegally. This comes after Hillary Clinton's campaign said it would join a recount effort in Wisconsin. Trump's allegations of widescale voter fraud originated in conspiracy theory circles, and have been debunked, but there's nothing in the law preventing the nation's next leader from trafficking in falsehoods.

In fact, as a candidate, Donald Trump was wrong more than he was right.

According to Politifact's Truth-O-Meter, 231 of the 331 statements Trump made during his presidential campaign — nearly 70% of what he said — was deemed either "Mostly False," "False," or "Pants On Fire."

Many of those false statements were attacks directed at his opponent, former Secretary of State Hillary Clinton, who was wrong just 26% of the time.

Trump's claims were either ignorant and misguided, or they were outright lies.

Legal experts say that ambiguity is one reason politicians almost never bother suing each other for not telling the truth. Because of their celebrity, people like Trump and Clinton have much more to lose by hauling their opponents into court for libel suits they stand to gain.

"It's just not worth it," Stephen Solomon, associate director of the Arthur L. Carter Journalism Institute at NYU, tells Business Insider.

'Actual malice'

The truth is, people can sue anyone or any company if they feel they've been defamed or slandered. For everyday folks, they need to show the statements were wrong and published with negligence. But public figures are the subject of more scrutiny, so their burden of proof also includes "actual malice." They have to prove the libelous claim was made on purpose or with reckless disregard for the truth. "That's very hard to prove," Solomon says.

The logistics of suing someone are another issue. As much as politicians want to preserve their image, lawsuits are incredibly expensive and time-consuming, Solomon adds. Even if the defamed party wins, the election will be over by the time the court reaches a verdict. The defamation will have done its damage.

What's more, there could be untold damage to the politician's reputation for them having brought the suit.

Undecided voters could also see the move as a sign that the candidate is too petty for political office. But the larger drawback is that the suit will inevitably lead to a discovery process, in which the politician would have to divulge private information they want to keep secret. If the politician's goal is to maintain their image at all times, discovery could end up doing more damage than if they'd never brought the suit at all.