I suppose the Brexiter argument is that we want to get out of the grip of the EU, therefore trade has to be made more difficult, via border checks, customs, veterinary checks, etc. This will cause an economic hit, but will be compensated via new trade with rest of the world. It sounds a huge gamble to me.
Also, the right wing are in charge, so it is feeding off English nationalist fantasies, but really England is for old white people, and is in decline.