It appears Sen. Arlen Specter (D-Pa.) got the memo about running in Democratic primaries in Pennsylvania: Put on your hard hat, because attracting support from unions is key.

This could not be more clear than in the former Republican’s first three television spots, which hit the airwaves on Wednesday. Specter, who has the backing of every major union in the Keystone State, highlights blue-collar workers in each spot — which, according to online reports, are airing on broadcast networks in Pittsburgh, Erie and Altoona, as well as on cable stations in Philadelphia.

The spots are also notable because Specter does not mention his party affiliation, despite the fact that he faces a May 18 primary battle against Rep. Joe Sestak (D), who has at least a $5.1 million bank account. Sestak is trailing Specter by at least 20 points in the polls, although the two-term House Democrat has yet to go on television.

Specter’s longtime media consultant, Chris Mottola, produced the spots.