Perhaps, but people were saying the same thing about Wisconsin and we KNEW there were people from out of state being bussed in to vote illegally. But Walker won by a big enough margin that cheating didn’t matter. If Romney can do that in PA, no problem. But if PA goes from losing by 10% to losing by a tiny percentage, that almost certainly means that the other big swing states have flipped, and that means President Romney with the PA irregularities being a footnote in history.
IIRC, there’s a popular vote percentage margin that, if a candidate crosses it, guarantees an electoral college win. I think it’s 2%.
If Romney carries Pennsylvania, I will go to bed early on election night. However, this state has always disappointed the GOP in national elections. There is no sound reason for Romney/Ryan to spend much money in the Keystone State.