Hillary's run for office reminds me very much like
Hubert Humphrey.  
She can't shake the war.

I think Gore's main advantage is that he can put the war behind him.
He can say "I opposed it from the beginning, but now I'll deal
with the consequences as best as I can".
He doesn't have to re-explain his position at every stop.
In the meantime he can run on the environment, an issue almost
everyone supports.