People assumed the same about ObamaCare. They're repeating the same thing about its chances of passing. Yet behold it did. What sort of witch craft is that. Oh that's right, we don't decide they do, and we can predict the outcome to say one of the outcome is absolute is a flat out lie.
Perhaps you should re-read dangerous and unusual weapons. Then check to see if the court ever considered an assault weapon something that falls under that. The actual truth is it's very possible that they would ban the weapon, just as it's easily as possible they don't.