Obama close to slamming the door

DES MOINES, Iowa — Sen. Barack Obama on Tuesday took a big step toward becoming the Democratic presidential nominee, amassing enough additional delegates to claim an all-but-insurmountable advantage in his race against Sen. Hillary Rodham Clinton.

While Clinton's campaign continued to make a case that she could prevail, Obama used the results from contests in Kentucky and Oregon to move into a new phase of the campaign in which he will face different challenges.

Those include bringing Clinton's supporters into his camp; winning over elements of the Democratic coalition such as working-class whites, Hispanics and Jews; and fending off attacks from Sen. John McCain, the presumptive Republican nominee, especially on national security.

Obama's obstacles were underlined by a lopsided defeat in Kentucky, where just half of the Democratic voters said in exit polls that they would back him in the general election.

But under the rules used by Democrats, Obama's showing in Kentucky and his performance in Oregon were likely to be enough to allow him to secure a majority of the delegates up for grabs in primaries and caucuses. He has portrayed that threshold as a yardstick for judging the will of Democratic voters.

"We have returned to Iowa with a majority of delegates elected by the American people, and you have put us within reach of the Democratic nomination for president of the United States of America," Obama said, standing in front of a moonlit Capitol in Des Moines.

But as Obama moved closer to making history as the first black presidential nominee, he stopped short of declaring victory in the Democratic race, part of a calibrated effort in the remaining weeks of the contest to avoid appearing disrespectful to Clinton and alienating her supporters. Instead, he offered her lavish praise.

"Sen. Clinton has shattered myths and broken barriers and changed the America in which my daughters and your daughters will come of age, and for that we are grateful to her," Obama said.

Clinton, declaring victory in Kentucky, made clear she had no intention of stepping aside before the Democratic voting ends June 3. "This is one of the closest races for a party's nomination in modern history," she said. "I am more determined than ever to see that every vote is cast and every ballot is counted."

In a sign of confidence on the front-runner's part, party officials said discussions were under way to send Paul Tewes, a top Obama campaign aide, to the Democratic National Committee to oversee operations for the fall campaign.

And in a fresh sign that their race was coming to an end, Clinton and Obama pledged a united party for the general election.

"While we continue to go toe-to-toe for this nomination, we do see eye-to-eye when it comes to uniting our party to elect a Democratic president this fall," said Clinton, whose supporters Obama will need if he is to end eight years of Republican rule in the White House.

Clinton won at least 37 delegates in the two states and Obama won at least 23, according to an analysis of election returns by The Associated Press. All the Kentucky delegates were awarded, but there were still 43 to be allocated in Oregon, and Obama was in line for many of them.

He had 1,949 delegates overall, of 2,026 needed for the nomination. Clinton had 1,769 according the latest AP tally at press time.

Before all votes were counted in Oregon, Obama was gaining a 58 percent share to 42 percent for Clinton.

The former first lady's victory in Kentucky was bigger yet: 65 percent to 30 percent.

Obama marked the moment with a symbolic return to Iowa, the state that launched his campaign with a big win on Jan. 3. Obama's aides said they were increasingly concerned that the long fight with Clinton had given McCain a free ride in critical general-election states.

His appearance in Iowa, which looms as a battleground state in the fall election, also suggested a new focus on the coming fight against McCain, with Obama portraying McCain as a third term for President Bush.

The Republican primary campaign, Obama said, "was a contest to see which candidate could out-Bush the other, and that is the contest John McCain won."

Obama is scheduled to spend today through Friday in Florida, an important general-election state. Clinton also planned appearances in Florida today. In the next month, Obama will head to Michigan, Missouri, Pennsylvania and Ohio, even as he continues to spend time where the remaining three Democratic contests will be held.

The rally in downtown Des Moines on Tuesday night offered evidence of steps Obama was taking to try to unite the party. Thousands of telephone and e-mail invitations went out across Iowa, where McCain is already running television commercials. Those targeted were existing supporters of Obama and voters who backed other candidates earlier this year and will soon be asked to join the fight against McCain.

Beyond that, the results in Kentucky again suggested Obama's general weakness with white blue-collar voters.

Obama's aides disputed the significance of the findings, pointing to national polls that show him running strongly against McCain with those voters and arguing that Democrats would return to the fold as the contest between Obama and McCain took shape.

"There's enough evidence now in public polls that in a general election against McCain, in the states that will determine the presidency, [Clinton's] supporters are coming our way," said David Plouffe, Obama's campaign manager.

Since 1972, when exit polls first began, no Democratic presidential candidate has won a majority of white voters. The closest division was in 1992, a three-way contest when 39 percent of whites voted for Bill Clinton and 40 percent voted for the first President George Bush. In 2004, President George W. Bush defeated John Kerry among whites by 58 percent to 41 percent.

David Axelrod, the chief strategist for Obama, said he was not worried about the significant share of Clinton supporters who said they would be disappointed if Obama became the nominee.

He predicted a "natural coalescence" among Democrats after the nominating battle concluded because of a concern over the war, the economy and the direction of the country.

"We're going to reach out and try to unify this party," Axelrod said. "It will happen naturally based on a commonality of interests."

Obama's advisers acknowledged that the campaign would need to deal with a perception of weakness, at least among critical party members. In particular, contributors and supporters of Clinton worried that Obama was suffering because of attacks on his relationship with his former pastor, the Rev. Jeremiah Wright, as well as on his patriotism.

They said Obama is likely, before the nominating convention, to deliver another major speech addressing questions about race, patriotism and his relationship with Wright.

To offset the voters who may rule out supporting Obama because of his race or other reasons, the campaign is working to register new voters. In Georgia, for example, 600,000 black residents are eligible to vote but are not registered. In Virginia, 200,000 black residents are not registered to vote.

Material from The Associated Press is included in this report.