Thats exactly what they'd do, work for less pay than Americans are willing to. We need to go after companies that hire illegal immigrabts but obviously, the government can't seem to do that. Next best thing is to keep illegals out.
Get rid of illegals, wages go up, in simplified terms.
I would argue its not, after all there are many things handled both by the feds and the state. And texas already put up plenty of walls in more urban areas.
Australia doesn't treat it's people like citizens, rather as subjects. Totally different dynamic.