With the Iowa caucuses just days away, it's final exam time in the left blogosphere, with the big question posed by the dueling professor/pundit duo Paul Krugman and David Brooks at the New York Times:

Sen. Barack Obama: Is he a political naif or a political saint? Is he tough enough to change America? Discuss in a million words or less.

Obama has been a hard case for the liberal netroots. He's got undeniable liberal credentials: early and consistent opposition to the invasion and occupation of Iraq; support for civil liberties; far-reaching proposals on global warming. But he's also upset liberal bloggers by echoing conservative talking points on Social Security and attacking the individual mandate to buy insurance in the health plans of Hillary Clinton and John Edwards. (Full disclosure: the individual mandate is a signature issue of the New America Foundation, where I have my day job.) Obama speaks comfortably to evangelicals about faith and values while many in the netroots wish to demote God talk from politics.

There remain "liberal doubts that he has what it takes to fight for progressive values," Matthew Yglesias writes at The Atlantic. "Basically, you face the same choice over and over again — is Obama's undeniable ability to win sympathy and praise from the more mild-mannered and open-minded segments of the right evidence of his internal frailty or is it evidence of his ability to build a dominant political coalition?"

At the New Republic, Sean Wilentz, a leading historian of American politics and a Clinton supporter, scorns Brooks and other Obama fans for their "delusional style" of investing him with special powers of "intuition," self-knowledge, and "identity." Such epiphanies, part of "an ever-intensifying cult of celebrity personality-worship," remind Wilentz of the George W. Bush of 2000, regularly described as "comfortable in his own skin." "Eight years ago, defiance of reality in favor of delusions about instinct helped bring the incumbent president to the White House. A catastrophic presidency ensued — directed largely on George W. Bush's intuition."

Echoing Krugman, some liberal bloggers are desperate for a Democratic candidate who will be as tough a partisan as Bush. They judge Obama to be deluded about the possibilities of reaching common ground with Republicans or entrenched corporate interests like health insurers and the drug companies.

"Clinton and Obama both think that you can sit down and negotiate with these people, that they are reasonable and data-driven and deal in good faith," Matt Stoller writes at Open Left. "But they are not. They operate from a calculus of raw power, and evidence doesn't matter to them."

Others see Obama's inclusive approach as smart politics and effective communication. Ed Kilgore at Democratic Strategist points out that there are generally two arguments against Obama's stance, both questionable.

The first is that he gives up leverage if he reaches out initially to corporate interests and conservatives. As Mark Kleiman explains at The Reality-Based Community, it's not true that the only thing people "care about or ought to care about is the policy conclusion a candidate for President reaches, rather than how he reaches it ...

"Many people want to be listened to as much as they want to be agreed with. Those people will be, if not delighted, at least satisfied, if a candidate will say clearly that he understands their concerns and acknowledges the legitimacy of those concerns, even in reaching an answer they don't like. What they don't want is to be on the losing end of the culture war, ruled by people who have contempt for them and for the things they value."

The second issue is which approach wins elections. "While this is definitely a good year for populist rhetoric," Kilgore notes, "the idea that it's some sort of silver bullet that will produce the kind of majorities that will enable the next president to reject any sort of compromise and FDR his or her way to instant progressive victories is, well, a bit under-supported by the evidence."

Winning is about more than just votes, Armando Llorens at TalkLeft reminds us. "Politics is not a battle for the middle. It is a battle for defining the terms of the political debate. It is a battle to be able to say what is the middle ..."

Like a lot of the netroots, Llorens wants not just a winner, but a champion. "There is no question that Barack Obama has the potential to be a transforming political figure. His talent is immense. But it is my view that until he embraces being a progressive who fights for his beliefs, he will never be such a figure."