He compared himself to Ronald Reagan challenging Gerald R. Ford for the Republican nomination in 1976. “He was the pariah of the party,” he said. “Now people love Ronald Reagan.”

On the Democratic side, after being in Washington on Friday, Mrs. Clinton and Mr. Obama switched coasts on Saturday, campaigning in Maine , which holds its caucuses on Sunday. Both then headed to Virginia where they were due to address about 4,000 Democratic officials and activists Saturday night at the state party’s annual Jefferson-Jackson day fund-raiser.

The dinner stands as a major barometer of support among the state’s most dedicated Democrats with the two candidates virtually deadlocked in their quest for national convention delegates three days before Mid-Atlantic neighbors Virginia, Maryland and the District of Columbia hold their primaries.

Then comes a brief intermission, followed by a string of election nights, some crowded, some not.

The date of March 4 looms large, with 370 delegates in primaries in Ohio, Texas, Rhode Island and Vermont.

In Louisiana meanwhile, exit polls showed about one in five voters said gender was an important factor in their vote in the historic Democratic contest to nominate either the first black or first woman for president, The Associated Press reported. About as many said the same thing about race. Of those whites who said race was an issue in their vote, almost 9 in 10 of them voted for Mrs. Clinton, while blacks who said it was important voted 9 in 10 for Mr. Obama. The racial gap in Louisiana was more extreme than in many other states this year: 9 in 10 blacks voted for Mr. Obama, while 7 in 10 whites voted for Mrs. Clinton.

Unlike previous Democratic contests, there was apparently no significant gender gap, with men and women voting in similar ways, even across races. Mrs. Clinton won the votes of most white men, a group she has lost to Obama in some states but has tended to win in the South. Those women who said gender was important to their vote went 6 in 10 for Mrs. Clinton, while women who said gender wasn’t important went 6 in 10 for Mr. Obama.

Voters over 50 years old were much more likely than those under 50 to say they were looking for a candidate with experience, and those looking for experience voted overwhelmingly for Mrs. Clinton. While older whites favored change and experience about evenly, more than half of younger whites favored a candidate who would bring about needed change. But even though Mr. Obama tends to be associated with change in this campaign, most younger whites voted for Mrs. Clinton instead of Obama. Blacks of all ages favored change, and they voted overwhelmingly for Mr. Obama. Most younger voters were black, while most older voters were white.