Yep, it's just economics.  We need more immigrants!  We wouldn't have roofs or roads in my part of the world without them.  And they're the best rogueing crews!  Work damned hard for not much money.  Not many white people want to work that hard (me included).  Immigration makes everyone better off.  Let those immigrants get the jobs they need so badly, and let us have cheaper roofs, roads, and corn seed.  The USA is in grave danger of becoming geriatric Japan if we don't let in more immigrants.