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.

Republicans are going to court in Pennsylvania amid vote counting in the U.S. Senate election between Democratic Sen. Bob Casey and Republican David McCormick, with the contest headed toward a state-mandated recount.

Republican Dave McCormick leads Democratic Sen. Bob Casey by about 28,000 votes, under the 0.5-percentage-point threshold for an automatic recount under state law.