Rather bitter election results, which will no doubt produce lots of mostly baseless attributions of blame.   My British friends should read Achen and Bartels' book Democracy for Realists, written before Trump, but they got him and his effect on Republicans exactly right, but their evidence is not limited to the United States.   Many group identities in the U.K. are now tied to Brexit, and the Tories were the party of Brexit.  The smear campaign against Corbyn surely didn't help, but I would be surprised if evidence emerges that it played much of a role in this outcome.   The supremacy of Parliament, including in constitutional matters, bodes ill for the future now that the Conservatives have a commanding majority.

ADDENDUM:  Some of the charts here are revealing:  in particular, the collapse of the UKIP vote since 2015 basically tracks the gains for the Conservatives in 2019; it's a reasonable hypothesis those voters migrated to the Tories.