An automatic recount has been triggered in the U.S. Senate race in Pennsylvania between Bob Casey and Dave McCormick. Here's how the recount will work.

The U.S. Senate election in Pennsylvania between Democratic incumbent Sen. Bob Casey and Republican David McCormick is headed for a statewide recount, as counties continued Wednesday to sort through outstanding ballots and the campaigns jousted over which ones should count.

Republican Dave McCormick won the U.S. Senate election in Pennsylvania, Decision Desk HQ projected on Thursday, beating Democratic incumbent Bob Casey in an important win for Republicans hoping to capture a majority in the chamber.