Pennsylvania’s U.S. Senate race between three-term Democratic Sen. Bob Casey and Republican challenger David McCormick could help Republicans pad their newfound majority in the chamber in a battleground state contest that is one of the nation’s most expensive this year.

As of early Wednesday morning, Pennsylvania’s nationally watched U.S. Senate race between Democratic incumbent Bob Casey Jr. and Republican challenger Dave McCormick was still too close to call. While Casey held a lead for much of the campaign,