WASHINGTON — As the race for the Democratic presidential nomination rounds the Labor Day turn and begins the stretch run, the pre-race form book is in tatters.

Senator Clinton of New York is the first woman with a real shot at winning the White House, but her gender has barely registered as an issue. Senator Obama of Illinois, running a strong second, is the first black American to become a major contender, but what little controversy there has been over race has come from the black community raising the issue of his cultural ties.

As for a former senator of North Carolina, John Edwards, who showed well as the Democratic vice-presidential candidate in 2004, he’s got the smile, the personal fortune, and the strong resume that are supposed to give candidates an edge. But, so far, he’s failed to break free.

And the thing that’s ripped up the form book is not Democrats. It’s President Bush. With an unpopular war driving his approval ratings to record lows and his party reeling from scandal to scandal, Mr. Bush has created an environment in which Democratic voters — and many independent voters too — seem to be looking first and foremost for change.

All across the country, voters appear ready to overlook such historically deal-breaking issues as race and gender and under-nourished resumes, focusing instead on personality and character in their quest for something new.

Exactly how much change voters want, and whether the attitudes of Democrats choosing a nominee in early 2008 will reflect the feelings of voters as a whole come Election Day, are open questions.

But for now, the unusual and the unexpected are the winning combination, as Priscilla King, 67, of Bow, N.H., suggested during an Edwards event in August.

She turned out to hear Mr. Edwards, but she’s partial to Mr. Obama — for a reason most analysts had considered a potentially disqualifying handicap: the first-term Illinois senator’s lack of experience.

“He’s fresh,” she said. “He’s inexperienced, and so far, experience hasn’t gotten us too far.”

The feelings Ms. King expressed at the Edwards rally illustrate something else about the Democratic race: Issues are not uppermost in their minds.

Ms. King’s husband is diabetic. The medical care he needs is so expensive that they’re left with only $62 a week to live on. If policy were what counted most, that should make Ms. King a natural Edwards supporter.

Mr. Edwards has put forward a health care reform plan that experts consider the most detailed and carefully crafted of any major Democratic candidate. If enacted, it could relieve the Kings’ financial pressures.

But despite Mr. Edwards’s careful attention to her story or the substantial nature of his plan, she is still taking a close look at Mr. Obama.

The topsy-turvy nature of the race is evident even on the Iraq war, the issue Democratic activists care most about.

Mrs. Clinton has remained the front-runner despite her vote to authorize Mr. Bush to attack Iraq, and her present position stops well short of calling for immediate withdrawal of American troops.

She says she would end the war as president, but she doesn’t say exactly when. And she would leave some troops in place to keep terrorists “on the run.”

To be sure, differences among the candidates on Iraq can seem small. Governor Richardson New Mexico wants American troops out in six months. Mr. Edwards said it might take nine months. Senator Biden, a Democrat of Delaware, would need 12 months.

Or consider how close some candidates stand on the high cost of medical care and the role that corporations should have in revamping the system.

Here is Mr. Obama in Iowa City, Iowa, describing the drug and insurance industries and their place in future discussions of health care reform: “While they’ll get a seat at the table, they don’t get to buy every chair.”

Here is Mr. Edwards in Hanover, N.H.: “You give these people a seat at the table, they eat all the food.”

Mrs. Clinton’s stance is harder to pin down. Health care was nearly her political undoing in her husband’s first term in the White House. He put her in charge of drafting a comprehensive plan, and it turned into one of his most resounding presidential defeats. Now, Mrs. Clinton is proceeding gingerly. She has called for universal health care but, unlike Messrs. Obama and Edwards, has not released a plan to bring it about.

“Her policies have not been bold,” said Robert Reich, who has known Mrs. Clinton since college and served as Secretary of Labor in the Bill Clinton administration but now describes himself as nonaligned.

“Her caution and her hearkening back to the good years of the ’90s might also serve to help Obama and hurt her own candidacy in terms of who is the truly new and transformative candidate.”

More than policy, what the Democratic candidates are selling is biography.

Mr. Obama has the most unusual, and it seems to be a plus. His mother was American, his father Kenyan, and he spent much of his childhood living abroad. He attended Harvard Law School, then went into community organizing and politics.

His life story appeals to those seeking something different. It’s also made him a hard target for rivals: He hasn’t done any one thing long enough to build a record to shoot at.

Mrs. Clinton has the opposite problem: She has been in the public eye so long that a significant number of voters have negative opinions about her — and she hasn’t found a way to change those minds. Among Democrats, a solid majority wants her to win the nomination, but those who oppose her seem implacable.

“If she gets the nomination, I will not even vote,” said Pat Steinfort, of Mason City, Iowa, a retiree. “I don’t like Hillary, period. She’s too strong-minded.”

Mrs. Clinton’s unfavorable rating in June was 44%, compared with 24% for Mr. Obama and 32% for Mr. Edwards, according to a CNN poll.