He will be judged on how much he evens up the country. Putting the Brexit fiasco to one side for the moment, people who wouldn't normally voted Conservative wanted a change. They've seen that local and national government hasn't stopped the loss of jobs and boarded up shops etc. They've seen a rise in crime, difficulties in getting GP appointments, etc. They believe local government is at fault, whereas the truth is that 10 years of Conservative government has cut local government funding.
I'm sure we'll have all sorts of PR exercises in five years time, but most people really aren't that stupid. My feeling is that it won't be so much about the Conservatives, but whether the Labour Party can produce a credible narrative. If it can't, people will continue to vote Conservative.