Mitt Romney walked out of his campaign jet at Pittsburgh International Airport here Tuesday afternoon and was met by an unexpected sight: hundreds upon hundreds of supporters packed into the top and middle levels of a nearby parking garage, cheering the candidate’s arrival.

A visibly moved Romney, clad in a white shirt and slacks, stepped into the late afternoon sun and walked across the tarmac to a spot near a metal fence separating him from the supporters in the garage…

“That’s when you know you’re gonna win,” he said as he walked back across the tarmac and into an SUV that carried him off to his second stop of the day.