Unless the anti-Romney vote is evenly divided among the three remaining viable ant-Romneys. Then he can win with 30 percent or even 25 percent.
I didn't think it possible for McCain to win in 2008. That's what a divided field does - changes the dynamic.
In this case, Romney is no John McCain, and that’s really saying something about Mitt Romney. There’s no way he will match McCain’s 2008 performance in SC. In my opinion Romney will have a difficult time exceeding his own 2008 performance - 15.3%. That leaves a lot of room for two and probably three others to exceed his vote total.