Campaign ‘08: The Pennsylvania primary

Clinton greets her supporters after winning the Pennsylvania primary.   (Carolyn Cole / Los Angeles Times)

Hillary Clinton signs autographs after her victory speech.   (Carolyn Cole / Los Angeles Times)

Clinton greets supporters before her victory speech in Philadelphia.   (Carolyn Cole / Los Angeles Times)

Bill Clinton reacts as he listens to his wife Senator Hillary Clinton address her supporters.   (Carolyn Cole / Los Angeles Times)

Chelsea Clinton applauds as her mother, Sen. Hillary Clinton, addresses her supporters.   (Carolyn Cole / Los Angeles Times)

Hillary Rodham Clinton supporters react as CNN projects her as the winner of the Pennsylvania primary.  (Carolyn Cole / Los Angeles Times)

Clinton supporters celebrate her victory in the Pennsylvania primary.  (Carolyn Cole / Los Angeles Times)

In Blue Ball, part of Pennsylvania’s Amish territory, a horse-drawn buggy rolls past a polling station.  (Carolyn Kaster / Associated Press)

Sen. Hillary Clinton greets supporters outside a polling place in Conshohocken.  (Robyn Beck AFP/Getty Images)

Sen. Barack Obama says “cheese” while posing with children at a day care center in Philadelphia.  (Emmanuel Dunard AFP/Getty Images)

Two girls outside a barber shop in Philadelphia watch an Obama campaign appearance.  (Emmanuel Dunard AFP/Getty Images)

Poll workers stand near a wall plastered with campaign posters in Philadelphia.  (Tom Mihalek / Associated Press)

Election worker Barbara Jackson holds open the curtain of a Philadelphia polling booth after helping Mary Faust vote.  (Matt Rourke / Associated Press)

A voter leaves a polling place at the London Grange in London, Pa.  (Keith Srakocic / Associated Press)

A worker at the Park Hyatt Philadelphia at The Bellevue -- Hillary Clinton’s election-night headquarters -- checks the podium.  (Carolyn Kaster / Associated Press)

Barack Obama and his wife, Michelle, depart their jet for another campaign stop Tuesday in Pennsylvania.  (Scott Olson / Getty Images)

Barack Obama and his wife, Michelle, greet Philadelphians after a visit to the Major League barber shop in that city. Obama also campaigned Tuesday in Pittsburgh.  (Emmanuel Dunand AFP/Getty Images)

In Pittsburgh, Steelers’ owner Dan Rooney, left, accompanied Barack Obama and his wife, Michelle, visiting patrons of Pamela’s P&G Diner on Tuesday. Later Obama told reporters: “We closed a big gap. We were down 20. This is always an uphill climb but what we feel is we’ve made significant progress.”  (Scott Olson / Getty Images)

At Pat’s King of Steaks in Philadelphia, Barack Obama and his wife, Michelle, dine on cheese steaks and fries Tuesday as Pennsylvanians go the polls.  (Scott Olson / Getty Images)

Political yard signs compete in the Wynnefield neighborhood of west Philadelphia.  (Jacqueline Larma / Associated Press)

Volunteers for Hillary Rodham Clinton stand outside a polling station in Butler, Pa., Tuesday.  (Jeff Swensen / Getty Images)

Hillary Rodham Clinton visits outside a polling station Tuesday in Conshohocken, Pa.  (Joe Raedle / Getty Images)

Hillary Rodham Clinton greets people on a visit to Boccella’s restaurant in Conshohocken, Pa.  (Joe Raedle / Getty Images)

Hillary Rodham Clinton holds a news conference outside a polling place in Conshohocken, Pa., Tuesday.  (Elise Amendola / Associated Press)

Clinton visits Boccella’s restaurant in Conshohocken, Pa.  (Joe Raedle / Getty Images)

Election workers do the paperwork with a voter in Conshohocken, Pa.  (Joe Raedle / Getty Images)

A polling station worker official assists a voter in Butler, Pa.  (Jeff Swensen / Getty Images)

A woman mixes child care with voting in Butler, Pa.  (Jeff Swensen / Getty Images)

Voters cast their ballots in Butler, Pa.  (Jeff Swensen / Getty Images)