Obama targeted Ohio as part of the firewall from day one and has put 100 million into Ohio bashing romney for 6 months. Plus OH, has early voting that started 1 day before the first debate.
PA has minimal early voting and relatively few ads which allowed the real Romney to show through.
Yes, PA and OH are now battlegrounds.
Michael Barone has written about PA also supporting Romney because of Obama’s war on the suburbs and the middle class.