Well it seems that he is in favour, perhaps he doesn't share your opinion of them.
Europe is being swamped with Muslim immigrants who will if not checked change the culture of this Christian, albeit nominal, continent. I do not want to see my grandchildren and their progeny subject to Sharia Law. Why would that be described as prejudice, where your desire to preserve Jewish culture is not?
Voting for Brexit here in the U.K. was not necessarily to keep out Eastern Europeans who can assimilate easily, it was to keep out economic immigrants from without the EU who once in because of the 'open borders' policy could legally settle here. It is this which accounts for the rise of nationalism in Europe, not a return to Nazism.
In the U.S. at least the culture of the immigrants from the South is Christian, not so here.