Congress has done nothing about securing the borders since the last time we were forced to give amnesty in the 80’s, so the whole thing has been premeditated.
Rewarding illegals simply leads to more threats the next time they demand something. Why should they pay attention to the rule of law when marching around yelling threats gets them what they want? McCain has lost his mind.
There may well be riots if we don't pass immigration "reform". But if that is true, then riots are likely inevitable no matter what we do; the longer we wait before working to remove the invaders, the worse the riots will be when they do occur.
Thus, even if McCain is right in a small part of his statement (riots may occur), he's absolutely wrong in the conclusion he draws.