Barack Obama scored a clean sweep of five weekend contests, eroding rival Hillary Rodham Clinton's narrow lead in the Democratic presidential race and prompting the former first lady to reshuffle her campaign staff in a bid to stop his momentum.
For now, at least, the wind is at Obama's back. Clinton replaced campaign manager Patti Solis Doyle with longtime aide Maggie Williams ahead of nomination races Tuesday in Virginia, Maryland, and Washington, D.C., where polls published Sunday showed Obama leading.
The two states and the U.S. capital all have a sizable number of black Democratic voters, a constituency that has aided Obama in earlier contests.
Clinton lost in Maine on Sunday, a day after the New York senator and former first lady was stung by defeats in Nebraska, Washington state, Louisiana and the U.S. Virgin Islands. She is struggling to overcome Obama's financial and political rally that came on the back of his impressive showing in last week's "Super Tuesday" series of Democratic contests in 22 states.
The Democratic nomination is far from decided, with weeks or months of campaigning still ahead. Clinton is an experienced, well-financed campaigner certainly capable of pulling off more surprise wins, as she did Jan. 8 in New Hampshire.
In the latest overall totals in The Associated Press count, Clinton had 1,136 delegates to 1,108 for Obama. The totals include so-called superdelegates, which are party leaders not chosen at primaries or caucuses, free to change their minds. A total of 2,025 delegates is required to win the nomination.
In Maine, with 99 percent of the participating precincts reporting, Obama led with 59 percent of the vote, to 40 percent for Clinton. Obama won 15 of Maine's delegates to the national convention and Clinton won nine.
Obama, who seeks to be the U.S.'s first black president, was buoyant after his weekend winning sweep. He even won a Grammy on Sunday for his audio version of his book "The Audacity of Hope: Thoughts On Reclaiming The American Dream," beating former Presidents Bill Clinton and Jimmy Carter in the best spoken word album category.
"I have the ability to bring people together," he said. Because of that, he said, "I think I can beat John McCain more effectively," he said, challenging the presumptive Republican nominee for November general elections.
McCain, too, was nursing Saturday and Sunday losses. He took the weekend off from campaigning despite embarrassing, but not pivotal, losses against preacher-turned-politician Mike Huckabee in two Republican races on Saturday. Huckabee, a favorite of evangelical Christians, beat McCain in Kansas and Louisiana, highlighting the difficulty the veteran Arizona senator faces in convincing the party's core right-wing blocs that he is one of them.
McCain, however, remained far ahead of Huckabee in the delegate count, and retained his virtually assured nomination that came on the back of rival Mitt Romney's decision to suspend his campaign. McCain has 719 delegates out of a total 1,191 needed to secure the Republican nomination. Huckabee had 234 delegates.
Since his string of Super Tuesday wins, McCain has concentrated on wooing conservatives who view him as a political maverick on key issues like immigration and tax cuts. The former Vietnam prisoner-of-war and decorated Navy pilot secured a boost Sunday when Bush referred to him in a taped interview as a "true conservative." But the president also stressed that McCain must do more to win over conservatives.
Bush's embrace could prove troublesome for McCain by reducing his appeal to independent voters in the November election. Bush reached his lowest approval rating in The Associated Press-Ipsos poll on Friday as only 30 percent said they approve of his job performance.
McCain narrowly won the Republican race in Washington state on Saturday, but Huckabee's campaign on Sunday called the final results in that state "dubious." His campaign chairman, Ed Rollins, accused the state's Republican Party chairman of calling the race too early for McCain - leaving 1,500 votes uncounted when the two candidates were just 242 votes apart.
Washington's state Republican Party chairman, Luke Esser, said by Sunday evening that McCain's lead had narrowed, but only slightly, with about 93 percent of results in.
Huckabee, a former Arkansas governor, on Monday resisted calls from some Republicans for him to abandon his campaign. He told NBC's "Today" show that "it's not a healthy thing for our party to sort of become lethargic, say it's (the presidential race) is over, have a coronation."
McCain appeared likely to rebound on Tuesday in the next Republican contests. The Mason-Dixon polls showed the Arizona senator leading Huckabee by nearly 30 percentage point margins in both Virginia and Maryland. The Republicans also compete in Washington, D.C., on Tuesday.
Former President Bill Clinton visited black churches in Maryland and Washington, D.C. in a bid to cut into Obama's huge lead among black voters.
New polls released Sunday showed Obama leading by 16 percentage points in Virginia and 18 percentage points in Maryland. The polls conducted Feb. 7-8 by Mason-Dixon Polling & Research Inc. had a margin of error of plus or minus 5 percentage points.
Clinton is looking for a big rebound in the high-stakes March 4 primaries in Texas and Ohio.