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.

The tight margin in the Senate race between Sen. Bob Casey, D-Pennsylvania and Republican Sen.-elect Dave McCormick has triggered an automatic recount under Pennsylvania law.

Republican David McCormick is projected to defeat Sen. Bob Casey (D-Pa.) in one of the nation’s preeminent battlegrounds, according to Decision Desk HQ, adding to the party’s margins after it took back control of the upper chamber earlier this week.

Unofficial returns in the race between Senator Bob Casey and Dave McCormick have triggered a mandatory recount under state law.

Pennsylvania's US Senate race between incumbent Democrat Bob Casey and Republican challenger Dave McCormick is going to an automatic recount. We talked to political expert Berwood Yost from Franklin and Marshall College about the recount process and what has happened historically.

Dabe McCormick's staffers say the legal dispute will have no bearing on the outcome of the U.S. Senate race against incumbent Bob Casey,