By Jessica Benton Cooney, CQ Staff

Illinois Sen. Barack Obama won Sunday’s Democratic presidential caucuses in Maine, a victory that gave him a dominant weekend sweep over New York Sen. Hillary Rodham Clinton . Obama prevailed in all four states that held the first Democratic nominating events after last week’s “Super Tuesday.”

Results released by the Maine Democratic Party showed Obama led Clinton by 59.5 percent to 40.5 percent, with 99 percent of the precincts reporting in the presidential preference vote at caucuses held in 420 towns and cities around the state.

Arden Manning, executive director of the Maine Democratic Party, said in a release, “I think his victory in Maine this weekend will provide Senator Obama with momentum going forward. However, this campaign is far from over. Barack Obama ran an aggressive grass-roots campaign in all corners of the state, and that is the right kind of campaign to run if you want to win in Maine.”

Manning added that state Democratic Party Chairman John Knutson announced that he has pledged his vote to Obama as a “superdelegate” to the Democratic National Convention. Knutson had stated last week that he would support the candidate who won the caucus vote.

As has been the case in every state that has held Democratic nominating events so far, Maine Democratic officials say turnout for their caucuses was exceptionally high. The number of participants far surpassed the caucus record of 17,000 voters set in 2004, according to Arden Manning, executive director of the Maine Democratic Party. Nearly 45,000 attendees had been tallied with nearly all precincts reporting, despite snowy conditions that hindered travel in much of the state.

And as in all but a very few states, Democratic voter enthusiasm greatly exceeded that of Republican voters in the state. The Maine Republican caucuses, held Feb. 1-3, drew just about 5,500 participants — a figure narrowly exceeded in the Democratic contest by absentee ballots alone. Former Massachusetts Gov. Mitt Romney won the Maine GOP event with 52 percent of the vote, but effectively ended his campaign Thursday after failing to score the big Super Tuesday wins he needed to stay in competition with front-running Republican Arizona Sen. John McCain .

Just as the Maine Democratic outcome concluded the best stretch of the campaign so far for Obama, it made a rough stretch even rougher for Clinton. Her Maine defeat came a day after Obama trounced her in caucuses held in the states of Washington and Nebraska and won by a comfortable margin in the Louisiana primary.

The Maine results also came in just hours after news broke Sunday afternoon that her campaign manager, Patty Solis Doyle, had stepped down and would take the position of senior campaign adviser. Maggie Williams, who like Doyle is a longtime Clinton aide, has taken over as campaign manager.

Clinton has stayed head-to-head with Obama, if not slightly ahead, in the overall delegate count by scoring key early primary victories in states such as New Hampshire, California, New York and New Jersey. But Obama has ruled in the caucus states, taking clear victories in 10 of the 12 that have voted so far. Caucuses tend to benefit candidates with strong activist voting bases, and the charismatic Obama fits that description.

He also has generally put much more money, time and organizational effort into caucus states than Clinton, but that was less the case in Maine. Obama campaigned in the state but so did Clinton; her husband, former President Bill Clinton; and their daughter, Chelsea.

Obama’s roll is widely expected to continue through this Tuesday’s regional “Chesapeake Primary” even in which the delegate distributions in Maryland, Virginia and the District of Columbia. Obama, who is seeking to become the nation’s first black president, has been dominant among black voters so far in the campaign, and all three jurisdictions voting on Tuesday have sizable black constituency that make up large parts of their Democratic primary electorate.

The Clinton camp, even before Sunday’s Maine loss and the campaign shakeup, was seeking to set expectations low for Tuesday, saying Maryland, Virginia and the District of Columbia are all favorable turf for Obama, and pointing to big events ahead in Ohio and Texas on March 4 as those in which Clinton — once the prohibitive front-runner for the Democratic nomination, would turn the contest definitively in her favor.

First posted Feb. 10, 2008 8:22 p.m.