LONDON — British voters head to the polls Thursday for their first general election outside the European Union. But in so many ways, the Brexit dream has already died.

All the key Vote Leave characters have left the stage. Five years after winning a landslide election Boris Johnson is out of parliament, making millions from speeches and newspaper columns. Michael Gove has quit politics rather than suffer life in opposition. Dominic Cummings spends his time writing blogs about Dostoevsky, TikTok and the CIA.

As the architects of Britain’s departure from the EU contemplate a decade out of power, the country they envisaged during the 2016 referendum campaign looks further away than ever.