In MA in every single election there are AT LEAST 4 different positions held by dems, running unopposed. In that case I vote for former Bruin & WAAF radio host Lyndon Byers by write in.
I'll be damned to hell if I EVER vote for ANY MA dem.
Don't know if Pa. election laws are different but I can never recall seeing a empty ballot position, there have been some where the same person runs on both parties but there has always been a name there as well as a place for a write in. In the case of one person running on both tickets I normally just don't vote for that position (wife gets mad if I put her name in) I just think that if a person can get into any elected office on either ticket, anywhere then it just shows total voter apathy.