You absolutely don't have to be "illegal" for the Haitian thing to be a threat. They've "deported" dozens of citizens at least, by arresting them, then taking them out of state to where their family and legal representation can't find them or communicate with them, and then threaten to keep them in those dangerous facilities indefinitely without key items for life including medicine or edible food until they give up and agree to be "deported."

And yes, he was absolutely implying a threat to do that to the alleged Haitian unless they backed off. He was just drunk enough (and vicious enough as a person) that he couldn't read the room to see that a more friendly approach was his best tactic. So apparently just instilling fear is the go-to. Wonder why his wife doesn't want to be near him and he's fighting for custody of his kids.