Oh man..you ask me difficult question there.
My seat of the points calculation is telling me that lots of primaries are still left after Feb 23, 2016. If conservatives do not unite behind one candidate by then, and keep splitting conservative voters, Jeb will be the nominee.
There are not enough conservative voters in the country to place both Governor Walker and Senator Cruz ahead of Jeb Bush. Recall how 2012 turned out? Ricky & Newt fought to the bitter end, splitting conservative voters, and clearing the path for Mitt.
Makes sense.
I think it will be difficult to get the voters to unite, though, depending on how the debates go. If Walker or Cruz does a Rick Perry, that would make it easier. It would be best if one of them would bow out gracefully and endorse the other. Which would be harder to do if the campaign gets nasty, as they typically do. (It would be easier if one would offer the other a VP spot.)