Sen. Barack Obama narrowed Sen. Hillary Rodham Clinton's lead in the fight for Democratic presidential delegates Saturday, sweeping three states, while Sen. John McCain hit a detour on his march to the Republican nomination.
Obama won Louisiana, Nebraska and Washington by wide margins as former Arkansas Gov. Mike Huckabee won Kansas and Louisiana, and McCain won a tight race in Washington.
None of the results reconfigured the delegate counts that will settle the nominations, but for Democrats they set the stage for the Maine caucuses today and the so-called Potomac primaries Tuesday in Maryland, Virginia and Washington, D.C.
Clinton and Obama remain locked in a showdown that might not be settled until the August convention in Denver, and each sought to make the case on the trail Saturday that each is better situated to defeat McCain.
"If our nominee is running against someone with the legendary background of John McCain -- Democrats need to think about this," Clinton said in Orono, Maine. "Because we're picking a nominee we expect to win. We cannot take four more years of more of the same."
In addressing an audience in Virginia after his sweep Saturday, Obama sought to cast Clinton and McCain as part of the same Washington establishment, and said the defining issue of the Democratic campaign was which candidate is most likely to effect political change.
"That's a debate we can win," Obama said.
Despite McCain's setbacks Saturday, the table remained set for the Arizona senator to eventually gather the 1,191 delegates he needs for the Republican convention in Minneapolis-St. Paul beginning on Labor Day.
After last week's Super Tuesday slate of contests -- which effectively ended the campaign of former Massachusetts Gov. Mitt Romney -- McCain faces only Huckabee, who swept the Kansas caucuses and the state's 36 available delegates Saturday, and U.S. Rep. Ron Paul of Texas, who has managed to win a sliver of the total needed.
Huckabee narrowly beat McCain on Saturday in Louisiana, but with less than a majority of the vote.
Under the state party's rules, that means the primary might not lead to any candidate being awarded delegates.
The results show that despite McCain's commanding lead for the Republican nomination, social conservatives are still willing to back someone else.
And they reflect the continuing divide within the party.
Huckabee celebrated the Kansas win and vowed to continue his campaign until someone receives enough delegates to seal the nomination.
"Earlier this morning, I said I didn't major in math, I majored in miracles. It looks like my victory in Kansas is one of them," Huckabee said. "Clearly I am pleased by these results, but it is onward and upward to Virginia and Maryland."
McCain, who was endorsed by Sen. Sam Brownback of Kansas after Brownback ended his own Republican presidential run, campaigned in Kansas with a single news conference in Wichita, said Corrie Kangas, the state party's political director. McCain did not campaign Saturday.
Huckabee made four stops in Kansas on Friday, helping him win his sixth state in less than a week.
"Huckabee held several rallies, and I think that weighed in on the results," Kangas said.
Campaign manager Chip Saltsman said in a statement: "It was an important victory, especially after the pundits spent the past few days saying this campaign is over. Kansas said, 'Not so fast.' "
On the Democratic side, Obama celebrated his sweep in a speech before the party's Jefferson-Jackson fundraising dinner in Richmond, Va.
"Today the voters from the West Coast to the Gulf Coast to the heart of America stood up to say 'Yes, we can,' " Obama told the enthusiastic crowd. "We won North, we won South, we won in between, and I believe that we can win Virginia on Tuesday."
The Obama campaign cast the three-state sweep as part of a broader endorsement by rank-and-file Democrats. He also won caucuses in the U.S. Virgin Islands, with three delegate votes at stake.
"They see in Barack Obama the best chance to beat John McCain in the fall, unite our country, take on the special interests, and confront the challenges facing working families," said Obama campaign manager David Plouffe.
Interest ran so high in Washington that the state party's online caucus-finder overloaded. The party diverted some traffic to the Obama campaign website and three other sites run by local Democratic groups.
Party spokesman Kelly Steele described the turnout as "record-shattering," perhaps double the previous record of 100,000 set in 2004.
The interest apparently centered mostly on Obama: He won two-thirds of the vote.
The Democratic Party allots delegates under a complex formula based on both statewide vote and the vote within congressional districts, so the number of delegates Obama won was not immediately known.
But the margins made it clear that he had gained ground on Clinton.
The day's lineup of states played to Obama's electoral strengths: an organization that gets supporters to caucuses, and in Louisiana a large base of African American voters who support his historic run for the nomination.
Clinton, of New York, and Obama, of Illinois, were already looking ahead to the next contests.
Clinton, who also addressed the Jefferson-Jackson dinner, asked the audience to look to inauguration day.
"Someone standing on the steps of the Capitol will place his or her hand on the Bible and be sworn in as the 44th president of the United States," Clinton said.
"Our task tonight is to make sure that president is a Democrat."