Also, what's the message here? Let in illegals, or else Superman is going to rip your spine out?

Superman's mere existence is always a lethal threat. Being near him is like being near a lion you were 'assured' was safe. Yeah, maybe, or maybe it could flip out and rip you apart and there's nothing you can do about it.

When Superman says something like that, it's an outright threat, because if you say 'no' to him, does anyone think he's going to back down? He'll tear your legs off and laser your family to death for defying him.