WASHINGTON – Veteran Republican Sen. Arlen Specter of Pennsylvania abruptly switched parties Tuesday, a move intended to boost his re-election chances that also pushed Democrats within one seat of a 60-vote filibuster-resistant majority.

"I now find my political philosophy more in line with Democrats than Republicans," Specter said in a statement posted on a Web site devoted to Pennsylvania politics and confirmed by his office. Several Senate officials said a formal announcement was expected at mid-afternoon.