Here is Al Gore doing a Digg Dialogg where marijuana comes up. It sounds like qualified support for legalization. Interesting that he is advocating states rights.
Posner is a 7th circuit judge. He is one of the most highly respected judges in the country. Supposedly things like his views on the war on drugs are what has kept him from being in serious consideration for the SC. His age would now be playing a role. He is also quite prolific as he writes his own opinions (a rarity), published over 40 books, and has blogged to fill in the gaps on his most recent book about the economy.