For the masses it's a question of a failure of education leaving them vulnerable to the lure of nationalistic mythology and post-imperial bitterness. They see their standard of living drop, but they are proposing an action that will impoverish them. They are being encouraged to misidentify the causes of their decline, and are receptive to this, especially if it is delivered in a plummy voice.
For the wealthy elite it's just another way of ensuring their wealth is not redistributed and that the levers are in place for them to make even more. There is also a faction who desire a very right wing survivalist economy, with little state infrastructure. To them, the EU is the antithesis.
The opposition have had an open goal for several years, but cannot capitalise on this because of the cross-party nature of the Brexit issue. Besides, they are offering something which is unappealing to large swathes of the electorate, and far too easy for the right to smear in both the compliant state media and the print and screen media of their billionaire backers.
As the cherry on top of the icing, we now have a dishonest and incompetent chancer as our PM. He just made a speech readying the ground for a snap election which he will pitch as 'people vs parliament'.
I fear a large section of the electorate will fall for this.