Gingrich beating Romney in South Carolina is actually a good thing for Ron Paul. The delegates are getting all split up and it's going to be very difficult for Romney, or anyone to get enough, which could result in a brokered convention. Santorum will be dropping out soon as he has no money or organization to continue much further and isn't even on the ballot in 4 states. Gingrich, who is also missing from the ballot in 2 states, is going to split votes with Romney and take delegates away from him as Paul continues to pick them up little by little.
This race is a marathon, not a sprint. The campaign has a plan. They have money, organization, and grassroots support in many upcoming states like Nevada, Missouri, Maine, Minnesota, Louisiana, Wyoming, Montana, South Dakota, etc. They never expected to do all that well in South Carolina or Florida, so this doesn't hurt his campaign much at all. He will be in the race all the way to the convention and possibly steal the nomination.