Southeast PA goes blue. One of the most dramatic shifts comes in the Philadelphia suburbs. The Delaware County-based seat currently held by retiring Republican Pat Meehan moves to a near-Democratic lock, according to David Wasserman of the Cook Political Report. A Chester County-based seat held by Republican Ryan Costello goes from a GOP lean to a strong Democratic opportunity — and his toughest declared competitor, Democrat Chrissy Houlahan, would remain in the district. (Republicans wanted to cut her out.) The Bucks County swing seat held by Republican Brian Fitzpatrick inches left, making it practically dead even.