No, they don't. We had Brexit. It was a smörgåsbord of stupid like that.
"We want freedom of movement cancelled so EU folks can't come in here, "followed by "What do you mean we don't have freedom of movement and can't just live in Spain?"
"All immigrants gone!" followed by "why are there no cheap immigrants anymore for working in the field and drive trucks?"
"Close the borders!" and "Why is there suddenly this long line and why do we need custom checks and passports?"
"After we made it more difficult for foreigners to come here, we have less tourists. Somebody do something!"
"When we said you can't fish here, we meant we can still fish over there."
"Yeah, I know we cancelled all cooperation but we really would like the subsidies to continue."
You can keep going. There were enough predictions that this was exactly what would happen, it was ignored in emotional flurry, ideologies and name calling. Of course there is a lot of "why didn't anyone warn us?" afterwards. I conclude they're not really thinking, just mostly reacting emotionally and going along with the peer group who has a very high "F U I got mine" content.