As vote counting continues this week in Pennsylvania’s tight Senate race, attention is once again shifting toward the largest and most hotly contested tranche of remaining votes that could help Democratic Sen.

Election officials say 80,000 ballots remain to be counted then votes in all 67 counties will be tallied again.

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.