Romney won decisively in New Hampshire in 2012 too. What happened to him in North Carolina?
Gingrich won in SC because he attacked the press at the beginning of the debate there. Gingrich is more similar to Trump than to Cruz.
4 years ago the candidate backed by evangelicals was Santorum and he finished third in SC.
SC has open primaries just like NH. Independents will come out in droves for Trump. Cruz will be lucky if he finishes in second.