>

The quality of immigrants also makes a big difference in addition to the tolerance of the host countries.
The US attracts immigrants with a higher educational and socioeconomic status. Furthermore, those immigrants are themselves attracted to the American dream and are motivated to integrate and succede. Indians or Asians for example have achieved higher average income status. 
The only sore spot is the southern border which gets vilified even though it provides lots of cheap labor for basic industries.
Europe is kinda the opposite where their bulk of immigrants are not really interested in their culture or lifestyle and are just looking to make a living after being forced to leave their host country.
The guy from Afganistan doesn't give a shit about Swedish values. He probably thinks they are a bunch of degenerates, but really likes their free social welfare so he feels resentful and stuck
Globalism is retracting. It didn't so much fail as it has just run its course.
We will see a great age of protectionism and regional alliances. Countries self reliance will become important.
Immigration in a lot of EU countries has failed. They have failed to correctly assimilate the immigrants into their society. Say what you want about american culture but something about coming to america makes you american.....