My political opinions aside... if you pull two of the biggest conservative talkers for a conservative talk station, and barely make a blip... something's wrong.
Have you looked at the ratings for most of the major market stations that carry those two? For example, WOR in NYC or WLS in Chicago? They're both in the basement.
The way to do major market talk is all-local. That's what works in Boston, Los Angeles, and just about everywhere else. Put Rush & Hannity on your back-up station. Which may say a lot about what they're doing in Philly.