There are quite a few countries which consistently score higher than the US on democracy, overall freedom and press freedom indices, despite not having these absolutist freedom of speech provisions in their constitutions (if they even have constitutions). Because it's not about the piece of paper or what's written on it, is it? It's about the society and what it allows their government to get away with. If the US ever becomes an authoritarian dictatorship, it'll have the exact same constitution and reverence for Founding Fathers, plus a few extra Supreme Court decisions.

Broadcasters themselves aren't subject to pre-clearance; obviously, live TV exists.

> the most the government can do is stop you from repeating it and punish you for having done so.

Yes - and, because of this, Clearcast exists with a sort of "TSA pre-clear" role. If Clearcast pass it, it's very unlikely to result in subsequent legal action.

TV stations are in principle free to broadcast unrestricted ads live and deal with the consequences. Obviously, they have no interest in doing that.

> No; you publish it, and the most the government can do is stop you from repeating it and punish you for having done so.

Soooo.... if I approach a US tv network with an ad that explicitly shows naked people doing cocaine, and carries the message that drugs are amazing, and ask for it to be scheduled during the kids tv peak slot, the networks are going to say "Hey, cool, yeah we'll do that"?

This seems very unlikely to me. It seems much more likely their internal compliance departments will look at it and say "Nope". So much for "you publish it".

Because that's basically what's happened here - the UK networks have outsourced checks on advertising to a third party they own, which itself gets its advertising code of conduct from an industry association the networks are part of. The third party makes decisions about whether an ad is OK. If it's not OK then the networks won't usually want to air it.