Interesting comment and illustration that was made on the BBC programme last night, I think by David Vine, about during the last general election the economy was foremost in peoples' minds, now that's not the case and perhaps immigration is.
It might be interesting to adapt Maslow's heirarchy of needs and apply it to a nation's concerns.
For example, the lowest and most important need is for food, shelter, etc. The kinds of things that the human life will fail without. (and why basic human needs, like food, shelter, etc are most important in countries torn apart by war, before any kind of higher needs can be addressed.)
Then the next need is for safety and security, including financial security.
The third level is for love, belonging and family. Perhaps, this is where the nation is now feeling pressure, due to immigration and the fear of losing one's culture. Which, is of course, the message of division preached by the scare-mongerers and doom-sayers. Please note, it is emminently possible to discuss immigration without resorting to abuse!
After that comes the need for esteem, self-respect. It's difficult to understand how this can be achieved once the divisive policies of some politicians have permeated the electorate.
Then finally self-actualization, i.e the need to reach one's full potential.
So perhaps David Vine was intimating that the nation's concern has moved on from the second level need because national financial security is more reliable, allowing the nation to look for higher level needs to be fulfilled. IMO, those higher level needs have been corrupted by some politicians to further their own agendas.