Whoah man, way to fire shots at Kenny G. Musical taste aside the guy can play the saxophone.
I jest. //edit: in fact, I think if you read the article in its entirety, i think the analogy holds out. No one can deny that Kenny G can play the saxophone, but he holds the middle ground. There is no experimentation, he has not lead a musical revolution like Coltrane did.
I think that there was no way that Obama could have acted, no level of achievement that would have made him anything other than a disappointment to the liberals of America. At the end of the day, the vast majority of American politics (ESPECIALLY federal politics) is slanted towards the right. I am young, but I can't remember a time, nor can i remember reading of a time when this was not the case when compared to other places described as "Liberal Democracies". Obama's supporters and the Left in america set themselves up to be disappointed.
Conservativism runs very deep in this country, and is tied to nationalism with a pretty strong cultural thread. Realistically, there was NO WAY that Obama could live up to the expectations of being a "New Lincoln" (a theme he himself consciously played upon, irregardless of the fact that Lincoln himself wasn't the most liberal of folks in a modern context).
Has Obama been a good president? ... meh? He's had some high points (ACA, regardless of its problems is the biggest step america has made in socialized health care in decades). At the end of the day, Obama is, and has always been a politician. He was not your saviour, he was never going to single-handedly take a sledgehammer to bad public policies. It just wasn't going to happen. He was a change, and I think in many ways a change for the better (though much could be said about the military complex under his tenure), but he's still a politician like any other, with all of the inferences that that term is given in this country (and most of the world, frankly).