Exactly. People come here to search for a better life. If they have it back home, they won't bother to come.
That, and they're liberals. More than likely, they will vote for the Left if they did come here, and they will try to bring the same leftist ideas that rule their own lands with them. If Norwegians, Danes, and Swedes came here and started voting, they'd enact policies like universal health care or more taxes on the rich. You'll just hand over more votes to the Democrats, who see the Scandinavian states as a model to copy here in America.
Trump and his people just don't understand how far left people in Europe are. In America, white Protestant churches are trying to push women into domestic labor and away from any political activity or "manly" jobs. In Europe, white Protestant churches are not only down with LGBTQ feminism and women voting, but they're also anointing female lesbian bishops as if it's nothing out of the ordinary.