WASHINGTON -- On Super Tuesday, John McCain secured the Republican nomination. How did that happen? Simple. In the absence of a compelling conservative, the Republican electorate turned to the apostate sheriff.

In the beginning, there were two. There was America's mayor, Rudy Giuliani, determined to "go on offense." And there was America's maverick, John McCain, scourge of Iraq wobblies.

Both aroused deep suspicions among conservatives. Giuliani's major apostasy is being pro-choice on abortion. McCain's apostasies are too numerous to count. He's held the line on abortion, but on just about everything else he could find -- tax cuts, immigration, campaign finance reform, Guantanamo -- he not only opposed the conservative consensus but insisted on doing so with ostentatious self-righteousness.

The story of this campaign is how many Republicans didn't care, and felt that national security trumps social heresy. The problem for Giuliani and McCain, however, was that they were splitting that constituency. Then came Giuliani's humiliation in Florida. After he withdrew from the race, he threw his support to McCain -- and took his followers with him.

Look at the numbers. Before Florida, the national polls had McCain hovering around 30, and Giuliani in the mid-teens. After Florida, McCain's numbers jumped to the mid-40s, swallowing the Giuliani constituency whole.

On Super Tuesday, the Giuliani effect showed up in the big Northeastern states -- New York, New Jersey, Connecticut -- and California. McCain won the first three with absolute majorities of 51 percent or more. And in California, McCain-Giuliani (plus Schwarzenegger, for good measure) moderate Republicanism captured 42 percent of the vote.

Elsewhere, where Giuliani was not a factor, McCain got no comparable boost. In Oklahoma, Missouri, Arkansas, Tennessee, Alabama and Georgia, he could never break through even 37 percent. The vote was divided roughly evenly among McCain, Mike Huckabee and Mitt Romney (trailing). But these splits were not enough to make up for the winner-take-all big ones, all of which McCain won.

The other half of the story behind McCain's victory is this: There would have been a far smaller Republican constituency for the apostate sheriff had there been a compelling conservative to challenge him. But there never was.

The first messianic sighting was Fred Thompson, who soared in the early polls, then faded because he was too diffident and/or normal to embrace with any enthusiasm the indignities of the modern campaign. Continued...