He has been pretty clear and emphatic on this. Only a true xenophobe would object to selective, controlled, LEGAL immigration of people who will become Americans, carry their own weight and make a contribution to our society.
Of course, the problem is what we have now and what the Democrats want to maintain: Uncontrolled mass immigration of people with no skills and no resources who will refuse to assimilate, will make no contribution to society and, in fact, will be harmful to us, but who will reliably vote for the party that supports and protects them.
We could get some extra American workers if people had to do something for their welfare checks.