I don’t think it was the purists, so much as middle-of-the-road pro-lifers who went squishy on the war. That, combined with a luckluster GOP candidate for governor and massive vote fraud in Philly (as usual) did Santorum in.
Purists don’t account for the 19 points Rick lost by.
True. A huge chunk of that 19 points are the Reagan Democrats who felt free to vote for Casey even though they had supported and elected Santorum twice before and had no reason to abandon him, but they were happy to toss a bunch of Republicans for Democrats who claimed to be "conservatives."