I think South Carolina and Virgina have laws that will keep his name off the ballot
Moreover, I think that most-—not all-—of the GOP rank-and-file would support the nominee and see such an “end run” by a Yeb or Bush as a total betrayal. Which could be good. It could cause the much needed purification of the GOP, which, if it does not happen, will result in the GOP’s final destruction. I think 2016 is the last chance for the Republican Party as we know it.