Aside from the obvious fact that Lamb has gone into full Bob Casey stealth mode of shutting his mouth and pretending that you can trust him to not vote with Pelosi:
-Saccone could have really used an image consultant going into this. In his TV spots he looks like a walrus, and a sloppily-dressed one at that. Lamb looks like a Hollywood leading man by comparison.
-Saccone is in the PA State Legislature, which is not exactly a ringing ethical endorsement. The Dems can throw any kind of dirt at him about alleged graft and malfeasance, and 90% of the public will believe it.
-Republican voters are REALLY, REALLY PO-ed at having been deceived for so many years by Tim Murphy pretending to be onboard with their Conservative values. Frankly they don’t really trust any Republican now who claims to be.
-Lamb comes from a long line of old-school Democrat office holders going back generations. They were not radicals, and generally well-liked. So the name recognition benefits him.
-The Catholic Church could turn this race simply by pointing out that “personally opposed to abortion” is not “opposed to abortion”. But they won’t.