The US doesn't allow unfettered free speech, that would be insane (although people on HN may disagree). But it is definitely "extreme" - you can lie publicly,

The US doesn't allow unfettered free speech, that would be insane (although people on HN may disagree). But it is definitely "extreme" - you can lie publicly, knowingly, and with resulting damages, very easily; it is much more difficult to pursue charges against someone who does so vs in the UK. With regards to political speech, it's even less restrictive.