Racial and ethnic tensions, which really just leads to a dissolution of social cohesion, which increases violence and overall unrest.
Then some extremist government is voted in to not allow foreigners at all (AfD, etc), or even the same government is pushed to have extremely strict immigration laws (see Denmark).
I don't consider myself a nativist, since Singapore shows a multi-ethnic society in relative harmony can be done. But that relies on both the local population and the government to be willing to live as one cohesive and multi-ethnic society.
Then some extremist government is voted in to not allow foreigners at all (AfD, etc), or even the same government is pushed to have extremely strict immigration laws (see Denmark).
I don't consider myself a nativist, since Singapore shows a multi-ethnic society in relative harmony can be done. But that relies on both the local population and the government to be willing to live as one cohesive and multi-ethnic society.