Since I mistakenly predicted a narrow victory for Rick Santorum in the Wolverine State, you will forgive me if I exercise a bit of proprietorial interest in why he ended up losing, albeit not by much.

One theory, which I trotted out in my overnight post, is that he ran into the limits of social conservatism. According to this view, a vote share of thirty-eight per cent is about the maximum he could expect to achieve in a state like Michigan, where most of the vote is concentrated in urban and suburban areas.

The more I look at the polling data, though, the more I think that Santorum, if he hadn’t made some eminently avoidable blunders in the runup to yesterday’s vote, could have snatched a narrow victory. His mystifying decision to attack the sacred memory of John F. Kennedy, his bizarre attack on college education, and his ham-fisted attempt to recruit Democratic voters to his cause may well have alienated enough of his potential supporters to have cost him the election.

To be sure, Santorum had no chance of running his vote up to the mid or high forties, as Romney managed to do in Arizona, but if he could have edged it up just a couple of more points, he would have won. As I pointed out in the post on Monday, several of the opinion polls showed things breaking in his favor over the weekend, when Romney was blundering around talking about his wife’s two Caddies and his pals who owned NASCAR teams.

The network exit poll confirmed that Santorum had built up some late momentum. Among voters who made up their minds in the past few days, about a quarter of the electorate, he won handily: forty-three per cent to thirty-four per cent. But according to Karl Rove, who presumably had access to more granular data, among voters who decided in the final twenty-four hours the numbers were reversed: Romney won by eight points.

What turned late late deciders against Santorum? Rove’s theory is that it was the news, widely reported on Sunday and Monday, that his campaign had been robo-calling Democrats and reminding them that Romney had come out against the auto bailout despite supporting the Wall Street bailout. Underhanded tactics are nothing new in this election—Santorum was quick to point out that Romney’s campaign had employed robo-callers in other states—but the revelation enabled Romney to portray his rival as a vote-grubbing hypocrite. (Only a month ago, Romney said, “States should only allow Republicans to vote in Republican primaries.”) Rove is probably right that this was enough to shift some voters into Mitt’s lap.

Another thing working against Santorum was the gaffe he made on Saturday, when, during a speech promoting manufacturing jobs, he appeared to criticize the concept of college education. Referring to President Obama, Santorum said, “He wants everybody in America to go to college.” And he went on: “What a snob…. He wants to remake you in his image. I want to create jobs so people can remake their children into their image, not his.”

Santorum’s speech was supposed to be about promoting manufacturing jobs. If he had confined himself to saying that not all good jobs require a college degree, and there are many worthwhile and socially useful professions that people without one can enter, he would have been on firm ground. By reverting to culture-war rhetoric, he placed himself in opposition to the views of the overwhelming majority of Americans—as evidenced in this article from Bloomberg News:

With the economy still struggling after emerging from a recession, more than two-thirds of U.S. adults view a college degree as essential for getting a good job, according to a Gallup Poll published in August. And 94 percent of parents with children under 18 expect them to go to college, said Paul Taylor, executive vice president at the Pew Research Center in Washington. “It’s a near-universal aspiration,” said Taylor.

The other big news over the weekend was Santorum’s interview with George Stephanopoulos on ABC’s “This Week,” when he appeared to suggest that J.F.K.’s famous 1960 speech about the separation of church and state made him want to puke. Actually, what he said was more indirect. After Stephanopoulos brought up J.F.K.’s speech, Santorum said: “I don’t believe in an America where the separation of church and state are absolute. The idea that the church can have no influence or no involvement in the operation of the state is absolutely antithetical to the objectives and vision of our country … to say that people of faith have no role in the public square? You bet that makes me want to throw up.”

Strictly speaking, Santorum wasn’t criticizing Kennedy: he was engaging in of his typical rants about the secularization of American politics. But two days before a crucial election, Presidential candidates can’t expect the media to parse their words carefully. Within hours of his statement, the news was out: Santorum had attacked Kennedy. And it wasn’t just the mainstream media that ran with the story: even Bill O’Reilly joined in. During his Fox News show on Monday, he contrasted Santorum’s statement not just with Kennedy’s but with the words of Ronald Reagan, who, in 1980, referred to Kennedy’s avocation that his Catholicism wouldn’t affect his Presidency as “just so, and proper.”

“The problem for Rick Santorum is that he goes beyond defending people of faith, and that’s getting him into trouble,” O’Reilly told his viewers. And he went on: Santorum’s “saying that some policy matters should be decided on what is considered right and wrong in the religious realm. That would lead to anarchy because Americans are very diverse in their belief systems.”

When Bill O’Reilly is criticizing a conservative torchbearer on the night before an election, something has gone badly wrong in that candidate’s campaign. And the most bizarre thing is that Santorum’s outburst wasn’t even necessary to secure his base. With Newt Gingrich not even competing in Michigan, he was assured of the votes of the evangelicals and other rural conservatives in the west and north of the state. To beat Romney, he had to pick up enough votes in the urban and suburban southeast of the state—in counties like Macomb, Monroe, Washtenaw, and Wayne.

Macomb, once a stronghold of Reagan Democrats, was particularly pivotal. An area that is still more than ninety-per-cent white, it is heavily inhabited by families of Irish, Italian, and Polish extraction—Catholic families that not very many years ago, and perhaps even now, had photographs of J.F.K. hanging in their parlors.

According to City-Data.com, fully seventy per cent of the inhabitants of Macomb County that have a religious affiliation are Catholics. In a contest between an Italian-American Catholic and a WASPish Mormon, the advantage should have been with Santorum. But rather than winning Macomb, he ended up trailing Romney there by a margin of almost nine points: 43.3 per cent to 34.6 per cent.

Can I prove that Santorum’s criticism of Kennedy swayed some of these voters? No. But it certainly can’t have helped. And since I need an excuse for getting things wrong, I’m going to seize upon it and wield it as more evidence that it wasn’t me who screwed up: it was my dumb candidate. He could have won it. He should have won it. And he blew it!

Photograph by Joe Raedle/Getty Images.