bexit came before the trump election
Also, to be clear, are you using anti-liberal in the American political sense of the world liberal (i.e. progressive), or in on the classical liberal sense (which has some overlap with small-l libertarianism within US political circles)?
We talk a lot about Red China being a dystopian Orwellian state - but their inspiration came from the UK, both the novel and it's implementation.
Since Brexit immigration has ballooned, and those immigrating are no longer culturally similar Europeans but instead from outside Europe. This difference is whipped up by elements of the printed press and especially social media. Throw in a dose of American cultural imperialism leading to their problems infecting the U.K through increased communication (again social media, but more YouTube than Facebook in this case) and you have a lot of angry people.
Meanwhile the economy which suffered heavily from the response to 2008 was pounded by the double whammy of Brexit and Covid. Throw in a housing crisis that’s lasted nearly 20 years and you get a disastrous corpse.