When former senator Rick Santorum talks about how much he loves Jesus, or hates abortion, he is usually addressing a gallery that is hungry for such rhetoric, and likely to applaud with enthusiasm. But has anyone ever been elected president of the United States because of his religious credentials? And has any president (including Ronald Reagan) had any particular effect on outlawing abortion in America? The answer, to both questions, is no.
Which is why Santorum's nomination by the Republican party would be impressive to true believers – in the same way that the Goldwater and McGovern campaigns were inspiring to their troops – but resistible to the majority of voters. America is a center-right nation, but presidential elections in modern times have been largely decided by the wavering independents who hover in the middle of the political spectrum. It is difficult to imagine independents who once voted for Barack Obama, or disenchanted Democrats, voting for Rick Santorum in appreciable numbers. It is entirely possible to imagine independents, and wavering Democrats, fleeing from the Republican ticket because of Santorum's emphasis on social and religious issues of peripheral importance to a majority of voters.
It is true that former governor Mitt Romney has failed to "break out" from the crowded Republican field during this protracted political season, and it is true that he comes as close as anyone to personifying the sort of consensus/establishment candidate the GOP tends to anoint. But it is equally true that Romney has maintained the allegiance of a steady percentage of voters in the polls, even in the face of temporary surges by other candidates. Nor has there been any conspicuous loss of support in Romney's numbers. This does not necessarily make Romney the strongest candidate against Obama, or even the ideal candidate; but it does suggest that the anybody-but-Mitt sentiment is volatile while support for Romney remains steady.
Indeed, if a plausible challenger to Romney were to emerge from within Republican ranks, he/she would look not like Rick Santorum or Michele Bachmann or Rick Perry but like non-candidates who more closely resemble Mitt Romney than Rick Santorum: Mitch Daniels, Jeb Bush, Chris Christie. These are governors with conservative credentials and pragmatic reputations, not a resolutely right wing, religion-oriented senator who probably repels more potential voters than he attracts.