There is a difference. I am not sure of the long term effects of Steriods, especially since someone like Lyle Azado died of a brain tumor, and probably John Matusak's heart attack was related.
I think if Bush did Coke in eighties, I don't think there would be any residule effects. In fact, some 40 and 30 year old would give their left arm for the health GWB is in.
So you wouldn't vote for him because you are afraid that he would die while in office?