Obama is to travel today to Mississippi, where he is leading in polls ahead of tomorrow's primary. Clinton (N.Y.) will campaign in Pennsylvania, which will vote on April 22.

Still reeling from Clinton's wins in Ohio and Texas, Obama's camp sent out a memo to supporters titled "Doing Whatever It Takes to Win." It characterized Clinton's strategy for victory as "tearing Barack Obama down" and said her campaign "should stop telling the American people things that they know aren't true."

With both candidates settling in for a protracted battle that appears certain to drag on past Pennsylvania, Clinton's campaign continued to hit Obama over comments from Harvard professor Samantha Power, who resigned from his campaign Friday after being quoted calling Clinton a "monster." Power had also suggested that Obama's proposal on Iraq, calling for troops to be brought home in the first 16 months he is in office, was a campaign plan by which he would not be bound if he were elected.

"Once again, it looks like Senator Obama is telling voters one thing while his campaign says those words should not be mistaken for serious action," a memo from the Clinton campaign read.

With Obama holding an advantage of about 140 pledged convention delegates over Clinton, his allies argued strenuously that the outcome of the contest should be determined by delegates awarded to winners of primaries or caucuses, and not by the 796 Democratic superdelegates. Former Senate majority leader Thomas A. Daschle (S.D.), a co-chair of the Obama campaign, said it would be a "travesty" if Obama maintains his lead among pledged delegates but an advantage among superdelegates allows Clinton to win the nomination.

"I don't see how we could possibly do anything other than respect the will of the people who have voted in caucus and primary states all over the country," he said on NBC's "Meet the Press." "And what it would say to the world, to the country, that we'd overturn the verdict of those . . . elections would be travesty for . . . the party and for the country."

(WaPo, 3-10)