Worst in what regard ? In that she now risks seriously imperillng the UK economy and the future living standards of its people ? Or that she places the narrow, sectarian interests of both herself and the Tory Party above what is best for the nation ? Maybe it's her continuing obsession with prosecuting the result of an advisory referendum which was an affront to democracy.
Or maybe it's simply that she has now made the transition from being the nasty, right-wing, stubborn, stupid politician of renown to a risible, internationally discredited and ridiculed buffoon.
Still, if her legacy is to drive a stake thro the heart of the Conservative Party it may all have been worth it.