"Back in 1960, John Kennedy had to stress the distance between public life and religion," says Robert Schmuhl, a Notre Dame University expert on US politics, in an e-mail interview from London, where he is teaching this spring. For Santorum, "catering to social conservatives is one way he can appeal to an important Republican Party constituency in the primaries and caucuses."
Public concerns about whether a Catholic would make a dangerous president, while they may not have disappeared, have faded. By contrast, two-thirds of Americans today see religion as "losing influence" in US life, rather than gaining, according to a 2010 poll by the Pew Forum on Religion and Public Life. And many, especially among Republicans, see that as a problem.
When Kennedy was seeking the presidency, only a small minority of Americans felt that religion was "losing its influence," according to Gallup polling at the time.
The changes over the past five decades include a confluence of social and political forces. America has remained deeply religious, compared with other industrialized democracies. Yet the perception that religion is losing influence has been matched by the rise of what political analysts David Domke and Kevin Coe have called a "God strategy" in US politics.
Republican politicians, and to a lesser extent Democratic ones as well, have become more vocal about their religious faith – and have enhanced their connection with many voters as a result. They may not quite be kneeling, Tim Tebow-style, before each speech. But Mr. Domke and Mr. Coe argue in their 2008 book that Kennedy's speech conveyed "a welcome message then" that would be "almost unimaginable today."
Polls show that Americans want their leaders to be people with strong religious faith, says Greg Smith, a senior researcher at the Pew Forum.