 FACT: A major plot point to the movie is that "the same matter  cannot occupy the same space". According to the tagline, Maxs wife  was murdered 10 years prior. Over 10 years, the human body does not  contain much of the same matter it did when it started. Especially  since the body is approximately 72% water, which is constantly being  replenished. Add to this the food which is consumed that contributes  to cell repairs, and very little "old mass" remains. Hence when Max  throws the Senator at himself at the conclusion of the movie,  nothing should have happened, other than the Senators bouncing off  each other.