Former President Obama is hitting the campaign trail Thursday, campaigning for Vice President Harris in battleground Pennsylvania. Obama and former first lady Michelle Obama endorsed Harris within a few days of her campaign announcement, following President Biden's decision to withdraw from the race. The Thursday event in Pittsburgh marks the beginning of the former president's campaign swing through the critical swing states on behalf of Harris's campaign. Pollsters and political analysts have zeroed in on Pennsylvania, predicting the state more than any other will decide the winner of the election, which is now less than a month away. In the Keystone State, Harris leads her GOP rival former President Trump by a thin margin — 48.7 percent to 48.1 percent — according to The Hill/Decision Desk HQ's polling aggregate. The event is scheduled to begin at 6:30 p.m. EDT. Watch the live video above.