[semiotagonal]

In the US it is almost impossible for a public figure, especially a political figure, to win a libel lawsuit.

In theory, a deliberate, malicious false statement against a public figure would count as libel; but in practice basically everything is allowed. This prevents politicians from intimidating their critics with lawsuits.

EDITED TO ADD: In fact in the US there is pretty much a constant stream of false statements about every politician, and I can't recall any politician ever winning a libel case. Devin Nunes is trying currently, and basically making a fool of himself.