Hillary Rodham Clinton is rigid, cautious and steely. Barack Obama is dangerously inexperienced. John Edwards is a narcissistic hypocrite. Joseph R. Biden Jr. can’t express a thought in less than 25 minutes. Christopher J. Dodd is making sense but nobody’s paying attention.

But, then again, Rudolph W. Giuliani is hot-tempered and not particularly solicitous of civil liberties. Mitt Romney is a flip-flopping opportunist. John McCain is a doomed defender of the Iraq war. Sam Brownback is a hopeless religious conservative. Mike Huckabee is too, except that he’s lost a lot of weight, has a wicked sense of humor and, because of his second-place finish in last week’s (utterly meaningless) Iowa straw poll, might not be the dead-man-walking everyone thought he was.

That’s the 2008 race in a nutshell, and if the candidates (and the press) aren’t careful, that’s about all that’s going to be written, thought and said about the whole thing. This isn’t the first time an entire presidential campaign has been distilled down to the simplistic. Remember John F. Kerry? He was a phony Vietnam war hero who couldn’t make up his mind about the Iraq war. And Bob Dole? An old guy with a World War II injury stuck in a World War II reverie with a World War II view of life.

Battle of the narratives

The greatest danger any of the 2008 candidates face is to be caught in a narrative not their own, to have every misstep and every remark forced into an established storyline that brooks no change. Mitt Romney’s father, Gov. George Romney of Michigan, is the classic prisoner of a narrative. Mention his name to even the most sophisticated member of the political class and, in a peculiarly cruel version of word association, the phrase “brainwashed on Vietnam” will spill from the lips. Romney’s 1968 campaign was sunk when he used the word “brainwashed” in connection with the war.

Right now the narrative machine is at work on Sen. Obama, who has the bad luck to be young (thus the “inexperienced” notion) and a bit impulsive (thus the “irresponsible” label, tossed by Sen. Clinton, who added, for good measure, the words “frankly naive”). This episode provides an unusually stark case study of how a candidate’s narrative is built by a rival and by the press despite the efforts of the candidate, his staff and his advertising advisers to construct an entirely different narrative.

The narrative that Mr. Obama and his handlers are trying to nurture is one of a deeply committed one-time community organizer whose brilliance took him to the editorship of the Harvard Law Review and whose own background (father from Kenya, mother from Kansas) is a metaphor for American diversity and an eloquent expression of American hope.

For a while, Mr. Obama was doing quite well with that, a theme that is to be underlined (along with a faintly negative exposition on another American trait, ambition) in a forthcoming biography of the Illinois Democrat by Chicago Tribune writer David Mendell.

Foreign policy stance

Just as the candidates are devoting hundreds of thousands of dollars, or more, into burnishing their stories, their rivals and the reporters who cover politics are writing narratives of their own. The problem, for the candidates, is that their foes and commentators are fitting everything they do into the rogue narrative, not the official narrative.

Here’s how it’s rolled out in the Obama case. In a July 23 debate, the senator, in response to a question, said he’d be willing to meet some of America’s foreign-policy and security foes such as the leaders of Iran, Syria, Venezuela, Cuba and North Korea. Sen. Clinton said she would make no such pledge and the political establishment, a Greek chorus all its own, roared: Whoa there -Sen. Obama is being a bit too eager. Then Mr. Obama said he might consider using military strikes on al-Qaida positions in Pakistan. Sen. Clinton’s reaction: “You can think big, but remember you shouldn’t always say everything you think if you’re running for president, because it has consequences around the world.”

On the defensive

In these episodes Sen. Obama no doubt wanted to show his creativity, his independence from the starched shirts and striped pants of established diplomatic procedure and his willingness to take on tough national security issues. But Sen. Clinton wanted to make sure the very people who pay attention to early political maneuvering saw that Obama was inexperienced, maybe naive, certainly a little too quick off the draw, in rhetoric if not in actual military action. Obama tried to define himself. Clinton tried to define Obama.

In this case, as in so many, the candidate who tried to take the offensive has been put on the defensive by a candidate who sensed an opening, or an opportunity, or a chance to transform the characteristic that one candidate thought was a virtue into a liability that will dog him for the rest of the campaign. Advantage: Sen. Clinton.

I mention all this because I have sinned myself; the job of a political correspondent is to commit this sin of creating a narrative from time to time, just not to make a habit of it. Creating a narrative is how humans make sense of a complex, confusing world. But being a prisoner of a narrative is how humans surrender observation and thought for the sake of simplicity. Barack Obama needs to break out of his narrative. We need to watch to see if he can.