So why did Rick Santorum pull out victories in Alabama and Mississippi when the final polling showed him slipping into third place behind Newt Gingrich and MItt Romney? The answer, simply, is that the polls underestimated evangelical turnout. In Alabama, Public Policy Polling had the evangelical/non-evangelical percentage at 68/32; the actual number was 75/25. In Mississippi, PPP had it at 70/30; the actual number ws 80/20. As a result, Santorum's narrow evangelical pluralities--which PPP did estimate right--were sufficient to lift him over his rivals.
It's not uncommon for the pollsters to underestimate evangelical turnout in Republican primaries, and the reason seems to be that they miss the role that mobilization plays. Credit for that yesterday was claimed by the anti-abortion Susan B. Anthony List, which spent half a million dollars to help turn out voters for Santorum. And presumably the old religious right pastors' network was working. Overall, turnout was up compared to four years ago--10 percent in Alabama and 50 percent in Mississippi. So at least in states with big evangelical populations, Rick's mobilizers can beat Mitt's moneybags.