The party’s centrists, from Blue Dog Democrats to Wall Street, insist that he’s turned out to be far more liberal than they expected. The health care bill was too expensive. The deficits are too big. He’s been too hard on business interests, and on Israel. And what happened to bipartisanship?

On the left, meanwhile, Obama is deemed a disappointment for all the things he hasn’t done. The stimulus should have been bigger. The financial reforms should have been tougher. He should have withdrawn from Afghanistan. He should have taken the fight to the Republicans, instead of letting them obstruct…

Can Obama rebuild his coalition? Perhaps, but not the way he did the first time. He won the White House by being all things to all Democrats (and quite a few independents and even Republicans as well), by making each faction see its own values reflected in his candidacy.

But the days of soaring above the grubbiness of politics are over. If Obama wants to save his presidency, he may have to do it the old-fashioned way: not by transcending his party’s divisions, but by uniting his supporters around their common fears.