Democrats need 60-seat supermajority in Senate to get major bills passed . At the same time , five-term Pennsylvania Sen. Arlen Specter remains a high-profile target for conservatives enraged by his decision to switch from the Republican Party to the Democratic Party last year . Comment: GOP targeting vulnerable seats , including those vacated by Obama and Biden . Flipping could go both ways , with Dems picking up some GOP seats .
Democrats need 60-seat supermajority in Senate to get major bills passed . Comment: GOP targeting vulnerable seats , including those vacated by Obama and Biden . Flipping could go both ways , with Dems picking up some GOP seats .