Obama picks up Pa. endorsement expected to bring more votes

PITTSBURGH -- Barack Obama got a surprise boost in the last big state of the long Democratic campaign Friday with an endorsement from Pennsylvania Sen. Bob Casey Jr., while another Obama supporter sought to nudge Hillary Rodham Clinton out of the race.

Clinton leads by double-digits in Pennsylvania polls, and Obama hopes Casey's endorsement will earn him a second look from the state's white, working class and Catholic voters -- groups that have leaned toward Clinton in other Democratic contests this year.

Clinton, on the other hand, is hoping a victory in Pennsylvania will help persuade party superdelegates to support her and allow her to catch Obama in the race for National Convention delegates.

Sen. Patrick Leahy, a Vermont senator who endorsed Obama in January, said she was never going to win enough delegates, and he suggested she should throw in the towel in ''the interests of a Democratic victory in November.'' A number of Democrats have expressed concern that Republican John McCain is getting a head start while Obama and Clinton fight on.