The standard disclaimer: Yes, PPP is left-leaning (they’re Kos’s pollster) so you may, if you’re so inclined, conclude that they’re trying to depress Republican turnout/boost Democratic turnout in the upcoming special election with these numbers. And now the obligatory footnote: They were pretty darned accurate in last year’s presidential polling.

I’m skeptical that even a tarnished GOP nominee is vulnerable in a district like SC-1 that has a Partisan Voter Index of R+11 (which is why I thought the general election would be a walkover), but that’s what makes this data potentially significant. Is Sanford’s image so tarnished that he’d actually put the seat in jeopardy by boosting turnout among Democrats and anti-Sanford independents? And will Republican primary voters start to think twice about him now that they’ve seen these numbers? If ever there was a poll with the potential to affect the outcome of a race, it’s this one.

Sanford remains a strong favorite for the Republican nomination heading into next week’s runoff. He leads Bostic 53/40. The horse race numbers closely mirror his favorability with GOP voters- 55% see him positively to 40% with a negative opinion. If there’s a silver lining for Bostic it’s that he still has a name recognition deficit– 77% of voters have heard of him to 95% for Sanford- and among voters who are familiar with him he trails Sanford only 49/46. That suggests some possibility of closing as voters focus in on the choice between the two in the final weeks, but Bostic may just not have enough time.

Focusing in on the potential race between Busch and Sanford it’s surprisingly close for one simple reason- voters like Busch and they continue to strongly dislike Sanford. 45% of voters see Busch favorably to only 31% with a negative opinion. On the other hand Sanford is still stuck with a 34% favorability rating and 58% of voters seeing him in a negative light.

The big question for Sanford is whether the Republicans who don’t like him- 39% of them- will be willing to vote for him anyway in the general election. The undecideds in a Sanford/Busch race voted for Mitt Romney by a 77/12 margin in 2012 so they’re an extremely GOP leaning group but because of their distaste for Sanford there’s a chance that they’ll vote for Busch or more likely just stay at home if Sanford is the candidate. If Sanford can up his share of the Republican vote in the general to 85% once he’s the nominee that would probably be enough to put him over the top.

Busch leads Sanford 47/45 but ties with Bostic at 43, with Bostic obviously having room to grow if he can get his name recognition up. Case in point, compare the “not sure” lines in the two data sets below.

The numbers among independents are … not good (in fact, Bostic’s favorability overall is just 30/42), but you don’t need broad appeal to win a district this red. If he can raise his profile a bit, most of those “not sures” are likely to move his way. Rick Santorum’s going to try to help him do that: He announced this morning that he’s endorsing Bostic, whose base is among evangelicals, in the GOP runoff. If you’re an undecided Republican voter who’s interested first and foremost in holding the seat, he’s the obvious choice, no? The generic unknown nominee’s a safer bet in a heavily Republican district than the famous one known for skipping out for a few days as governor to visit his mistress on another continent.

Exit question: Will Huckabee endorse Bostic too? The race for the social conservative champion in 2016 is on.