David,
Of course the core Tory vote are the ruling class.

Of course they are not. They are ordinary people with no special powers or privileges.

SPB,
If there is free trade then no border infrastructure is required.There are differences across the border already, and smuggling is a constant problem already.
If there is not free trade between UK and EU there is still no need for infrastructure. The volume of trade across that border is tiny. Most of it is from large businesses that can submit there trade for tarifs as they do already for duties. Much of the remaining trade can be classed as local and not requiring tariffs. Smuggling will be an issue as it already is. Any lost revenue will overwhelmingly be from UK.

A closed border is completely impossible anyway. It is 300 miles long with about 200 crossing points, mostly remote. It can not be closed so we just make it work as well as possible and the police will continue to chase the smugglers.