Then there’s that fact that in a field as crowded as this one, it’s hard to believe that any candidate is going to get the “very conservative” space to him/her self. In 2012, Mitt Romney was the obvious establishment candidate. The three anti-establishment candidates (Rick Santorum, Newt Gingrich and Ron Paul), split up that very conservative vote. Santorum took the lions’ share with 36 percent, but Gingrich took another 26 percent and Paul siphoned off 7 percent. Meanwhile, Romney took almost half (46 percent) of the somewhat conservative and 48 percent of the moderate vote. In 2016, Ted Cruz, who is clearly gunning to be the face of the conservative wing of the party, will face a crowded field of candidates for that space including Rand Paul, Ben Carson, Scott Walker, Marco Rubio, Rick Santorum and Mike Huckabee.

To be sure, Bush doesn’t have the establishment vote to himself either as Walker and Rubio will provide strong competition for that segment of the electorate. In fact, it’s hard to believe that Bush will be able to dominate the somewhat conservative and moderate factions of the party as thoroughly as Romney did. Even Rand Paul should be considered a threat to Bush in this category. In 2012, for example, Paul’s father Ron picked up 14 percent of the moderate vote – his strongest showing among any of the GOP sub-groups.

Then there’s the issue of the calendar and the way delegates are awarded. Changes to RNC nominating rules in 2010 that were designed to help non-establishment candidates – such as allowing some states to award delegates proportionally instead of winner take all-weren’t enough to derail Romney. Those rules, as Jim Rutenberg outlined in a recent New York Times magazine article, have since been modified to further limit the possibility of a rogue or non-establishment candidate winning the nomination. Even those states that have proportional voting, for example, have different rules for how the delegates are doled out. Some by congressional district. Some by statewide vote. Some by a combination of both. In other words, as we saw in the 2008 Democratic primary fight, the calendar and the rules are going to be a critical – and not easily understood – factor in determining the nominee.