Illegals already have to register. There is almost no exemption if you are a male, and 18 to 25.
“Illegals already have to register”
Yes, but they don’t, and many of them find out that they have to when they get here, but still don’t, because of course a) they’re criminals breaking the law by being here, and b) they don’t want to end up in the big bad gringo army.