From my reading of the literature, yes, immigrants tend to boost domestic wages. Here’s some economic analysis and review of the literature if anyone is interested:
This. Won’t. Happen. The farming, construction, and restaurant lobby won’t let it happen. The borders won’t be sealed, because unguarded walls don’t work. Immigrants will be terrorized under a Trump administration. There may or may not be a drop in their number. But the effect won’t be large, because it’s the cruelty and racism which is the point, not white working class wages.
If the GOP did want to reduce immigration, they would penalize employers for hiring illegal immigrants. But they don’t, so they won’t.
Imagine what would happen if the GOP accidentally cut the agricultural labor force by 20%. That’s a level of chaos even Fox News would struggle to cover up.