Jay Cost eviscerates Obama's D- sociology (yeah I stole that trope from Peter Lawler) in trying to explain away opposition to his agenda.  I think it goes well with this smart paragraph by regular commenter Art Deco:

One gets the impression that his understanding of history begins and ends with the Democratic Party's received narrative and that he conceives of himself as a character in some tome by Doris Kearns Goodwin.

Obama had a long apprenticeship in politics that was in some ways diverse and in some ways narrow.  His lived experience is almost entirely on the left-of-center, but he isn't the creature of any one institution.  He has experience in issue advocacy, academia, and Chicago machine politics.  He had to learn how to speak to different liberal constituencies (the South Side and Hyde Park) at the same time.  He no doubt learned some lessons about the nuts and bolts of politics as well as how to take a cheap shot.  His apprenticeship (from the early 1980s to the mid-2000s) also coincided with the experience of feelings of marginalization by many liberals.  Republicans usually held the White House and the Clinton administration was something between a missed opportunity and a desperate rearguard action. 

Obama seems to have gone to school on selling a liberal activist agenda to the general public (he already knew how to talk to liberals) and then getting that agenda securely enacted.  This included constructing the cool, detached, pseudo-open minded style that serves an ideological politician especially well in reassuring swing voters.  It also included certain policy concessions.  He changed his mind on welfare reform.  He was pro-death penalty and talked out of both sides of his mouth on the Second Amendment (no biggie there, he can appoint Supreme Court Justices who will vote abolish the death penalty and neuter the Second Amendment.)  He tried to neutralize the Republican advantage on taxes by advocating (in the short-term) tax cuts for most combined with tax increases on high earners.  John Kerry had actually promoted this policy first, but Kerry (unlike Obama) had a long history of voting for tax increases and against tax cuts as a Senator.  Obama was of course willing to make spectacular bad faith promises like the one of a net budget cut.  There is something off about his attempts to create an appeal to non-liberal-leaning Americans.  Unlike Reagan, who learned to appeal to FDR-loving Democrats by talking to them at length, Obama seems to have constructed his appeals to non-liberals in isolation from them.  That is why he sometimes resorts to a sociology of smugness when things seem not to go his way.  Still, his appeals have worked well enough for Obama to get his way when it really mattered.   

The payoff for all these campaign concessions is to do something big for the liberal cause as President. Something big could mean using the opportunity of an economic crisis to pass a big spending increase (and pay off favored constituencies.)  If the economy turns around, the public would tend to identify Big Spending with prosperity.  It isn't working out well so far, but 2012 is far away and we'll see.  Something big could mean reordering the energy market in a "green" corporatist direction through cap-and-trade.  That ain't gonna happen anytime soon.  Above all, something big would mean adding a huge new middle-class entitlement and taking THE decisive step toward government-run health care. 

Even if it hurt his popularity in the short-run, such a health care law would ensure him a place in the Mount Rushmore/Hall of Fame/Valhalla of liberal historiography.  That would be far higher than the place of Bill Clinton, who had high approval ratings, but whose most notable policy accomplishments were a balanced budget and welfare reform.  FDR would love Obama best.  So when you get the chance, go for broke (in every sense.)  Once you have enacted the big change you can let the anti-majoritarian features of American politics (bicameralism, the filibuster, the veto) work for you rather than against you. You can also count on the tendency of government expansion to reorder interest group politics in a more statism-friendly direction.  You can hope that demagoguery (if you repeal health care reform children will die...) and people's natural risk aversion will scare enough people to prevent the GOP from reversing your policies, and once those policies are entrenched, the political incentives will tend to push policy in an  ever more statist direction.

None of this is to say that Obama is a good President.  He is a dangerous opponent with the skills to win elections and then enact and (potentially) entrench policies that I find destructive.  It is also why, for all of his weaknesses and blind spots, he is the most formidable domestic opponent conservatives have faced in generations.  And whatever happens this November, he is not beaten.