Republican David McCormick cut into Democratic Sen. Bob Casey's support in Philadelphia and its populous suburbs and built leads in the more GOP-leaning parts of the state, foreclosing the incumbent's pathway to victory when The Associated Press called the race Thursday.

But as the final margins are still being tallied, the Senate race in Pennsylvania remains open with both candidates at odds over a projected victor in the close election.,On Thursday, the Associated Press called the race in favor of former hedge-fund CEO Dave McCormick,