When you look at the history of the bills they introduced, sponsored and got passed, Obama has a proven history of not being afraid to go after things that will piss off lobbyists, he has a proven history of getting shit passed, and a proven history of being able to work together with the republicans to get things done. The guy can motivate the american people - that alone deserves some credit.
Hillary voted for the war on iraq, which she regrets and was ultimately (in the minds of most americans) a big mistake. Obama stuck to his guns and was against it. Who is more qualified?
More experience does not always mean someone is more qualified.