Keystone Contest

Confetti drops as Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y. addresses supporters on Pennsylvania primary night in Philadelphia, Tuesday April 22, 2008. Clinton won the primary with 55 percent of the votes to 45 percent for her opponent Barack Obama.

Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., celebrates with her daughter Chelsea Clinton at her primary election night rally in Philadelphia Tuesday, April 22, 2008.

Former President Bill Clinton and his daughter, Chelsea, flank Dorothy Rodham, mother of Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., as she speaks at her Pennsylvania primary election night party in Philadelphia, Tuesday, April 22, 2008.

Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., celebrates with Pennsylvania Gov. Ed Rendell at her Pennsylvania primary election night party in Philadelphia, Tuesday, April 22, 2008.

Democratic presidential hopeful, Sen. Barack Obama, D-Ill., right, and his wife Michelle acknowledge his supporters at Obama's Pennsylvania primary night rally Tuesday, April 22, 2008, in Evansville, Ind.

A line of vehicles leave the polling place during the Pennsylvania primary election in Cranberry, Pa., Butler County, Tuesday, April 22, 2008.

Omar Graybill works on his paper ballot while casting his vote in the Pennsylvania primary at St. John's Center United Church of Christ polling place in East Earl, Pa., Tuesday, April 22, 2008, in Blue Ball, Pa.

Maurice Scott, 8, seated, gets a haircut from Marcus Williams, right, as Rosa Fortt, left, asks a question of polling volunteer Eugenia Gary while voting in the Pennsylvania primary at Toni's Barber Shop in Philadelphia, Tuesday, April 22, 2008.

People vote in the Pennsylvania primary at a firehouse in Philadelphia, Tuesday, April 22, 2008.

An Amish horse and buggy rolls past a polling station for the Pennsylvania primary at the St. John's Center United Church of Christ in East Earl, Pa., Tuesday, April 22, 2008.

Primary election voters cast their votes at Blue Ball Fire Company, Tuesday, April 22, 2008, in Blue Ball, Pa.

Residents of the Fitler Square neighborhood of Philadelphia wait to vote in the Pennsylvania Primary at a neighbor's garage in Philadelphia, Tuesday, April 22, 2008.

Residents of the Fitler Square neighborhood of Philadelphia vote in the Pennsylvania Primary at a neighbor's garage in Philadelphia, Tuesday, April 22, 2008.

Democratic presidential hopeful Sen. Hillary Rodham Clinton, D-N.Y., left, walks with Anna Boccella on the way to a campaign stop at Boccellas Restaurant in Conshohocken, Pa., Tuesday, April 22, 2008, the day of Pennsylvania's primary election.

Democratic presidential hopeful Sen. Barack Obama, D-Ill., shakes hands with supporters as he leaves Pamela's Diner in Pittsburgh, Tuesday, April 22, 2008.

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