MACON, Ga. (AP) Democrats Hillary Rodham Clinton and Barack Obama, each claiming a pair of early victories, now leave the concentrated campaigning of Iowa, New Hampshire and South Carolina for an unwieldy and costly 10-day dash through 22 states that hold presidential primaries or caucuses Feb. 5.

Obama's surprisingly easy victory in South Carolina puts greater pressure on the New York senator to carry states she long has considered her strengths, including New York, Arkansas, Connecticut and the megastate of California.

Obama's overwhelming support from South Carolina's black Democrats boosts his hopes of winning three other former Confederate states voting Feb. 5: Georgia, Alabama and Tennessee.

The two candidates underscored those states' importance immediately. Clinton campaigned Saturday night in Nashville, and Obama traveled Sunday to Macon, Ga., and was then going on to Birmingham, Ala.

Despite his huge win Saturday, Obama faces serious challenges. He must improve his showing among white Democrats, who gave him only one-fourth of their votes in South Carolina. Even in Iowa and New Hampshire he never got more than 36 percent of the white vote, which was divided among him, Clinton, John Edwards and a few others.

Obama's campaign feels it will do well in caucus states because of its strong ground organizations, as it did in Iowa on Jan. 3. The seven states holding Democratic caucuses on Feb. 5 include Minnesota, Colorado and Kansas.

The South Carolina results were deeply disappointing to native son Edwards, who won the state's 2004 primary. He now will have to fight even harder for money, media attention and votes, as many Democrats see the contest as a two-person struggle.

Its next stage will be strategic, targeted and complex. Democrats award delegates based on the proportions that candidates win in each state, with no winner-take-all states. That virtually forces them to compete in every state to some degree.

"Now it's a delegate race," said Obama campaign spokesman Robert Gibbs, "so there's not a state you're not going to do a little bit in."

"This isn't going to be judged on, 'I won six states, you won this amount of states,'" Gibbs said.

But even the fundraising clout of Obama and Clinton is not enough to let them advertise or campaign extensively in all 22 states.

"I don't know how we're going to do it," Bill Clinton said before leaving South Carolina. "I don't know how they're going to do it."

The Clinton campaign is counting on strong showings in New York, where she handily won a second Senate term in 2006; Arkansas, where her husband was governor for 10 years; and California, where Bill Clinton was generally popular and where Hillary Clinton seems to run well among Hispanics.

The Clintons are less sure of New Jersey and will probably spend time there. Her campaign also hopes to do well in Arizona and New Mexico, largely on the strength of her popularity among Hispanic voters.

Both campaigns consider Missouri and Tennessee major battlegrounds. Clinton is advertising in northern California, Arizona, Connecticut, Delaware, Massachusetts, Missouri, New Mexico, Oklahoma, Tennessee and Utah. Obama also has ads in several states, and he will campaign in Kansas and possibly Missouri early next week.

Both campaigns will scrutinize South Carolina's results and exit polls for lessons. More than half of its primary voters were black, a vastly different scenario from Iowa, New Hampshire and Nevada. Clinton won New Hampshire and Nevada after Obama stunned her in Iowa.

But the South Carolina result shakes up the race yet again.

Obama did especially well among young whites, and he will continue campaigning hard in college towns and among young adults. That is a group, however, that historically talks about voting more than actually doing it.

His biggest challenge remains race. If he cannot expand his share of the white vote, Clinton may outpace him in many of the Feb. 5 states.

A major question is whether white voters in states with comparatively few minorities will embrace Obama more than they did in South Carolina. Racially divided voting occurs mainly in places with sizable minority populations, which explains why most white southerners moved to the Republican Party in the past three decades while blacks remain overwhelmingly Democratic.

Most white southern Democrats now are liberals or clearly willing to align with liberals. Most of them chose Clinton or Edwards in South Carolina on Saturday, and Obama cannot afford a similar dynamic in California, New Jersey, Illinois and other Feb. 5 states with fewer blacks.

He addressed the issue in his victory speech Saturday night. "The choice in this election is not between regions or religions or genders," he said. "It is not about black versus white."

"It's about the past versus the future," he said.

The Clintons' toughest decision may involve how best to deploy the former president. He remains tremendously popular among many Democrats.

But his occasionally heated jabs at Obama and reporters seemed to rankle South Carolinians at times last week, and there is widespread debate in political circles about the cost-benefit tradeoff for his wife's bid to win the job he once held.

Associated Press writer Beth Fouhy contributed to this report.