Dan Balz of the Washington Post draws on papers by political scientists trying to explain the political problems of the Obama presidency. Some blame Obama for trying to be above politics in 2008, offering a bipartisan vision that was impossible to achieve. Others say he exaggerated the effect of his rhetorical skills once president.
There's some wisdom in these analyses. American politics has been highly polarized for at least two decades. It's also sad but true that each of the last three presidents has been viewed as fundamentally illegitimate by a large segment of the opposition party. There are also deeper reasons for this situation -- the realignment of the parties into ideological opposites, the rise of safe congressional districts through clever redistricting, and the growth of influential interest groups outside of the party/electoral system. [I see nothing wrong with an interest group saying "we're right on corporate taxes, or relations with Taiwan, or prescription drugs. What I dislike is when those groups push for candidates using unrelated issues and hiding their real agenda.]
A more telling criticism of Obama comes from John Judis in the New Republic. He documents the inconsistencies in the administration's approach -- sounding a populist trumpet one week and sober nonpartisanship the next. Politicians should remember what harm an uncertain trumpet can do.