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.