For Trump, it doesn't matter whether an immigrant obeys the law, or owns a business, or has been here for decades, says Mark Brockway, assistant teaching professor of political science. “They are caught in the middle of Trump's fight against an invented evil enemy,” Brockway says.

“The job is a leadership role, where your task is to motivate people from wide-ranging, different disciplines to come together to define the problem as the same and then go about trying to solve it through multiple avenues. Everything I’ve heard about him certainly suggests that he’s got a lot of talent and capability to make him the ideal person,” says University Professor Emeritus Sean O'Keefe.

“If the U.S. stops even doing that—and it would be quite a radical policy change if the U.S. is unwilling even to sell weapons to European countries—then Europe will have to continue on the path it is already on, which is to bolster its own defense production capacity,” says Brian Taylor, director of the Moynihan Institute of Global Affairs.