WASHINGTON — Vice President Joe Biden said endangered Sen. Arlen Specter is the Democratic candidate the party is backing in Tuesday's Pennsylvania primary.

Specter is in a close race with Rep. Joe Sestak. Biden told KDKA radio in Pittsburgh after Specter switched parties last year, President Barack Obama made a firm commitment to the five-term lawmaker. Biden said Specter has the party's support and the AFL-CIO's. Biden also said he was surprised Sestak challenged Specter, but he said he never asked the congressman not to run.