The GOP's "Big 4"

[SPC]

I wouldn't could out Huckabee, he still could pull off a Iowa win.

Aside from Iowa and the Greater South, Huckabee only broke 20% in one contest before Romney's withdrawal (after which Huckabee became the generic anti-McCain protest vote and only won Kansas and Louisiana.) With a divided field, he could definitely win Iowa and possibly South Carolina, but in that scenario it seems that whomever wins New Hampshire would automatically become the frontrunner (as 2008 and 2012 proved). Even if Paul won New Hampshire, I would think that Republican powerbrokers would more likely prefer someone with an unorthodox foreign policy to an economic populist who could easily prove to be a national Todd Akin.

[SPC]

There are four (arguably five) major constituencies in the GOP primaries: 1) moderates, 2) mainstream conservatives, 3) very (social) conservatives, 4) very (fiscal) conservatives, and 5?)libertarians (although the last category is fairly novel and contains substantial overlap with the first and fourth categories). Looking back at the major nominating contests of the past:
1980: Reagan (2,3,4) beats Bush (1), Anderson (1), et. al (1)
1988: Bush (2, 1 to some extent) beats Dole (1), Robertson (3), Kemp (4)
1996: Dole (2, 1 to some extent) beats Alexander (1), Buchanan (3), Forbes (4)
2000: Bush (2, 3) beats McCain (1), Keyes (3), Forbes (4)
2008: McCain (1, 2 to some extent) beats Huckabee (3), Romney (4, 1 to some extent), Giuliani (1)
2012: Romney (2, 1 and 4 to some extent) beats Santorum (3), Gingrich (3 and 4 to some extent), Paul (5, 1 to some extent)

Admittedly, this analysis may be an instance of the Texas Sharpshooter fallacy, but I think it works heuristically to say that the person with the plurality of factions on their side wins the nomination in the end. The first category will go for Bush or Christie, with few other plausible options on the horizon. The third will likely gravitate toward Walker or Rubio, with Paul or Cruz having a shot as well. Fourth goes to Huckabee, with Cruz, Carson, or Perry having a shot. Fifth (if it still exists in sizable numbers) belongs to Paul. That leaves the second, which is usually the decisive category. I believe that Walker, Bush, or Rubio are the best fits for this category.

I believe the last two contests have demonstrated that the primaries serve less to generate momentum and more to weed out various aspirants for each category. For example, Huntsman and Giuliani ceased to be viable mantle-holders for category 1 when they failed to win decisive primaries, clearing the way for Romney and McCain respectively to obtain dominance of that category. Category 3 will be determined by Iowa, Category 1 by New Hampshire, and Category 2 by either New Hampshire or South Carolina.