Oh, please. There is no need for Casey to "drop the charade." You're right that he's in a good spot, but the man is a Catholic, and he can vote with his conscience with impunity if he so chooses. Because he is an incumbent, about the only thing that will get him out of office is if he so pisses off pro-life independents who voted for him (and I'm guessing that more than a third of all Catholics describe themselves as such) that they rally to the polls against him.
And in exchange, the Dims and the unions will make sure he has plenty of money and manufactured Philly and Pittsburgh ballots to comfortably stay in office, no matter how many pro-life "neanderthals" he hacks off.
JMO.