Well but Brexit still passed and Boris still won. There were signs that the Conservatives would be replaced by the Brexit party when they tried to filibuster Brexit, which is why Boris replaced May and won the election dramatically.
The UK is an anarchotyrannous shithole to be sure and it's a travesty people get arrested for tweets or that Darren Grimes got investigated for interviewing David Starkey, but my point is that it can't violate the fundamental invariant that you get the government and the referendum result you vote for. Eventually. And the home secretary
criticized the Grimes investigation (
archive).
A hypothetical uniparty USA would violate that invariant.