Republican Dave McCormick, an Army veteran and former hedge fund CEO, has unseated three-term Democratic incumbent Bob Casey Jr. in Pennsylvania’s nationally watched U.S. Senate race, according to The Associated Press.

After days of the race being too close to call, the Associated Press named Republican Dave McCormick the winner in the race for one of Pennsylvania’s two seats in the U.S. Senate, defeating incumbent Democrat Bob Casey. McCormick first addressed supporters at his election night party in Pittsburgh when the race was too close to call.

The Pa. race drew national attention for its potential to flip a seat from blue to red in the Senate, where Democrats have enjoyed a slim majority.