Without these kinds of policies you'll just see the rise of more "new-right" parties like One Nation in Australia and Reform in the United Kingdom (yes, I am aware both are not "new", but they are newly popular).
It turns out there is a sufficient amount of immigration that is disliked by the populace that they will dump support for long-standing parties in favour of those who promise change.
It turns out there is a sufficient amount of immigration that is disliked by the populace that they will dump support for long-standing parties in favour of those who promise change.