Following a narrow 0.43% lead for Republican David McCormick over incumbent Democrat Bob Casey, Pennsylvania will begin a recount due to the margin being within the mandated threshold. Controversies arise as some ballots with signature issues are being counted, despite state supreme court guidance. Several counties, led by Democrat commissioners, have moved to include undated ballots in the recount, sparking legal challenges from Republican groups. The final outcomes may impact the Senate's Republican majority.