A surprise for some early-morning customers at a Dunkin Donuts shop across from a school serving as a polling place in Washington, D.C.

Barack Obama, along with Washington Mayor Adrian Fenty, stopped by for some donuts and coffee for poll workers.

Obama is favored to win today's primaries in Maryland, Virginia and the District of Columbia.

Some 168 Democratic delegates are at stake. After winning five states in weekend contests, Obama is expected to come out on top in an area heavy with black and better-educated voters, blocs that have helped him win before against rival Hillary Rodham Clinton.

Clinton, meanwhile, is preparing to fly to Texas, which holds its primary on March 4th. While all but conceding losses today, the Clinton campaign is looking to stop Obama's momentum by winning in Texas and Ohio that day.

Asked about the March 4th contests, Obama says "it's very early." And he said he wants to get through today's contests first.

One the Republican side, John McCain is hoping to rebound with three wins after losing two of three weekend contests to underdog Mike Huckabee.