The problem is that people forget where Obama comes from: Obama is not a progressive. Obama is not centre-of-the-Democratic-party. Obama is pretty much smack bang in the middle of the US political landscape today. Take him back to before the Republican Party went totally off the rails, and he might've just as easily been a left wing Republican.

The "Hope & Change" looks a lot more successful when you judge it based on an intent of returning US politics to somewhere near the centre, than if you take the unrealistic proposition that it would bring the US to some point well left of Clinton which a lot of people seemed to have thought and hoped it might.