Republicans notoriously tend to pick the candidate who is next in line. A 21-year Senate veteran who had run once before, McCain was emphatically next, and it's almost as if the other candidates couldn't help but follow a migratory instinct to make him the front-runner. Huckabee kneecapped Romney in Iowa, and when he rose up himself to become a threat to McCain in South Carolina, Fred Thompson kneecapped him in turn (while barely ever saying a discouraging word about McCain). Romney was the only one to attack McCain robustly, but quit negative TV advertising after New Hampshire and could overcome him only in Michigan.
That was enough for McCain to forge a tenuous path toward the nomination: He lost self-identified Republicans by 1 point in New Hampshire; lost self-identified Republicans by 14 points in Michigan; and tied among self-identified Republicans in South Carolina and Florida. In other words, McCain is close to the presumptive GOP nominee without yet having won self-identified Republican voters in any primary -- a bizarre, and perhaps unprecedented, circumstance.
The typical strategy for winning the Republican nomination is the inside-out one pursued by Romney. Win the conservative base, then build out from there. McCain worked his coalition from the outside in. He had a lock on the moderate and liberal vote, then worked to win enough conservatives to inch over the top. He lost the 21 percent to 33 percent of voters in the early states who say they are "very conservative" by overwhelming margins. The battleground was the 32 percent to 35 percent of voters who are "somewhat conservative." McCain won them (barely) every place but Michigan.
It's hard to imagine a less likely path to the nomination. McCain's tenacity and indelible image as a truth-telling maverick have been indispensable, but so have the other candidates and -- yes -- the political stars. Keep rubbing the lucky nickel, Senator.