As one American syndicated columnist put it this week in discussing the importance of religion in US presidential elections, "no atheist or agnostic (or non-Christian) has a chance of being elected to any position in our country". But, added Scripps Howard News Service writer John M Crisp, once they're in the White House, "our presidents are pretty much free to practise their religions with whatever level of devotion suits them".
In other words, you might feel the need to talk a lot about God and his values on the campaign trail, but if you actually win the race, Americans are far more concerned about jobs, growth, national security and all of the things that affect a politician's ratings across the democratic world.
That's worth bearing in mind in the wake of Texas Governor Rick Perry's recent decision to run for the presidency. "He knows how to talk like an evangelical," said Richard Land, head of the Southern Baptist Convention's Ethics and Religious Liberty Commission. There's no mistaking that. At a huge gathering of the faithful recently he publicly asked Jesus to "save" America.
It's too early to say how strong his chances are, but it would be foolish to write him off. Texas is a strong base from which to launch a bid for national power, and his social and religious conservatism should give him some decent appeal among important sections of the electorate.
But will that same religious conservatism prove counter-productive among other groups, particularly Jews who, though small in number (less than two per cent of the population), can be important electorally in swing states like Ohio, Pennsylvania or Florida? Much depends on whether Perry and other such candidates come across as divisive or inclusive.
It seems unlikely there's much to worry about on that score. Most Christian conservatives in the US have good relations with their Jewish compatriots, and they're strongly supportive of Israel. "My faith requires me to support Israel," Perry averred in 2009.
That kind of talk could tip a portion of the Jewish vote in a Christian conservative direction, should Perry or someone like him get the candidacy.
Given the deep disappointment among many US Jews with President Obama's attitude to the Jewish state, Republican strategists are certain to make a pitch for their votes, 78 per cent of which went Democrat in 2008. Never say never in America. An appeal to Jesus might just swing it for the Jews.