A peculiar handicap of the statistically sighted is that they are congenitally astigmatic when it comes to seeing the "big picture." Without in any way forswearing my love of the NY Times' number guru, Nate Silver, I just gotta say: Nate, Nate, my boy, where the hell have you been and what have you been watching?
What propels today's question is Silver's matutinal musing in kind: "I’m interested in the question of what historians will see as the turning point when they look back on the 2012 Republican race." Silver offers several angles, from last night's primaries to Iowa ("or even before Iowa, in the early 'invisible primary' phase of the campaign, but I don’t think that squares very well with the volatility we saw after that point"), but here's my far shorter answer: There was no turning point; Romney's path was both linear and inexorable.
And that, I'm confident, is what historians will write. Serious future histories of the 2012 presidential contest will cough up some brief, obligatory acknowledgement of a pretend GOP primary season, and then they'll hie straight to the general -- because "serious" histories won't squander space on the laughable frauds and farcical loonies who, ahem, contested Mitt Romney.
It's still the primary season, yet already one must pry with a mental crowbar all those forgettable personages from one's memory bank. Let's see, there was some comely harpy who for months chanted little but "a ... one ... term ... president"; there was a waddling, corrupt has-been who sold and signed books and charged the price of a tank of gas for a digital photo; there was a combustible paradigm of ill-preparation from the "wind-swept prairies" of demagogic Texas; there was a tea-partying womanizer of profound intellect-arrested development; and, oh hell, I forget the others. But that's OK, they never mattered any more than the vaguely remembered ones.
The essential point being: Romney's path to the nomination was indeed linear and inexorable, but only because he faced no real competition -- said competition having long ago decided to wait until 2016.