“If you think they are all legal”
Yeh they are. Trump uses contractors who only hire legals. He stressed this in an interview. Could they have unknowingly hire one here and there? Who knows Maybe. But not intentionally.
And their subs? You know better than that and so does he. Unless I saw one of his standard contracts, I'm not believing a word of it.
You don't mention the hotels, kitchens, groundskeepers...