The Pennsylvania Senate race between incumbent Bob Casey, left, and his Republican challenger, Dave McCormick, is headed for a recount. All counties must complete their recounts by Tuesday, Nov. 26. Pennsylvania's Senate race is going to a mandatory recount despite the Associated Press calling it last week for Republican challenger Dave McCormick.

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.

Though Election Day is past, swing-state advertising isn’t. A new ad hit Pennsylvania airwaves Tuesday calling on three-term Democratic Sen. Bob Casey to concede the race the