Lest you think Obama is unaware of the religion gap, here’s a passage, from page 201 of his 2006 book, The Audacity of Hope:

The single biggest gap in party affiliation among white Americans is not between men and women, or between those who reside in so-called red states and those who reside in blue states, but between those who attend church regularly and those who don’t. Democrats, meanwhile, are scrambling to “get religion,” even as a core segment of our constituency remains stubbornly secular in orientation, and fears–rightly, no doubt–that the agenda of an assertively Christian nation may not make room for them or their life choices.

As the Obama campaign fights its way forward on the religion front, there no better text to keep in mind.