Here are just a couple of reasons just off the top of my head

#1 Ali is the most famous/recognizable fighter ever

#2 Ali got screwed out of money a couple times too and I believe he may be one of McCain's favorite fighters

#3 Ali is a cultural hero/icon and anyone who voted against such an Act would have surely caught hell because of it

#4 It had a better ring to it than the "Don King can't financially fuck fighters in the ass anymore" Act

Is that good enough??