unprecedented - yes, a misuse of the word, and mostly just exaggeration and political speak.
extraordinary - i don't see your objection to this word being used. please correct me if i'm wrong, but the supreme court does not regularly/often/most times/ordinarily strike down laws passed by congress. yes it has happened, but it is not a common occurance.
just seems like you are taking a pretty big jump here.
he talked up his bill, pretty much the way any politician would.