What can one say? Obama is a disappointment in so many ways. For sure, he has been thwarted and blocked at every turn by cynical, grotesquely partisan Republicans who care not at all about the national interest. Republicans in Congress are among the most vile people on Earth. (How's THAT for moderate commentary?!)
But it's also true that Obama has failed to show the sort of leadership that so many of us expected of him. Here is an interesting column in today's New York Times by Tom Friedman that makes a good argument to this effect. (Please note that my typical reaction to Friedman is that he is a totally arrogant, Gingrichian — i.e., faux intellectual – asshole who thinks he is god's gift to mankind, and I usually dismiss his putrid spooge.) But he makes sense here.
Also, see this rant by Chris Matthews (the MSNBC asshole whose arrogance is at least as bad as Gingrich's and Friedman's). He actually makes sense here, too.