American Grace - book

"How frequently you attend church, or interestingly, how frequently you say Grace ... measures like that, how religious you are, have a pretty strong correlation with how you vote and which party you prefer," Campbell says.

The God Gap In Voting

Another shift in the American religious spectrum is how religion correlates to political beliefs.

No matter what religion this putative Aunt Susan follows, knowing and loving her makes it hard to judge her.

It's called American Grace: How Religion Divides and Unites Us.

The Nones

One of the biggest changes over the past 20 years has been that more and more Americans, when polled, cite no religious affiliation at all.

So every American is sort of caught in this dilemma, that their theology tells them one thing, but their personal life experience tells them to be more tolerant."

It's called American Grace: How Religion Divides and Unites Us.

The Nones

One of the biggest changes over the past 20 years has been that more and more Americans, when polled, cite no religious affiliation at all.

The God Gap In Voting

Another shift in the American religious spectrum is how religion correlates to political beliefs.

American Grace: How Religion Divides and Unites Us
By Robert D. Putnam and David E. Campbell
Hardcover, 688 pages
Simon & Schuster
List price: $30

Read An Excerpt

"So it's now, roughly speaking, 35 percent [to] 40 percent of younger Americans … who say that they have no religious affiliation."

The God Gap In Voting

Another shift in the American religious spectrum is how religion correlates to political beliefs.

"How frequently you attend church, or interestingly, how frequently you say Grace ... measures like that, how religious you are, have a pretty strong correlation with how you vote and which party you prefer," Campbell says.

So every American is sort of caught in this dilemma, that their theology tells them one thing, but their personal life experience tells them to be more tolerant."

The America of today, Campbell says, has "managed to accomplish something that is historically and internationally unique — that we're a religiously devout country, a religiously diverse country and a pretty religiously tolerant country."

"We've reached a point where there really is a pretty stark political divide on the basis of, not so much the particular denomination you attend, but rather the intensity of your religious commitment," Campbell says.

The shift, Putnam says, is "a quite novel and interesting, significant development."

Robert Putnam and David Campbell
Louise Kennedy Converse/Simon and Schuster

David Campbell (left) and Robert D. Putnam are faculty at Notre Dame and Harvard universities, respectively.

The United States is a nation that was both founded by religious people and built around a guarantee of liberty from state-imposed religion.

For many years, the researchers say, only about 5 to 7 percent of Americans felt they belonged to no religion.

The religious landscape has changed substantially over the past three centuries, with the addition of faiths in America that range from Islam and Judaism to the Church of Jesus Christ of Latter-day Saints; today's landscape of worship includes megachurches with huge congregations, storefront tabernacles, spiritual advisers.

"We've reached a point where there really is a pretty stark political divide on the basis of, not so much the particular denomination you attend, but rather the intensity of your religious commitment," Campbell says.

More marriages across once-rigid religious lines.

It's called American Grace: How Religion Divides and Unites Us.

The Nones

One of the biggest changes over the past 20 years has been that more and more Americans, when polled, cite no religious affiliation at all.

The United States is a nation that was both founded by religious people and built around a guarantee of liberty from state-imposed religion.

The shift, Putnam says, is "a quite novel and interesting, significant development."

As for the Americans who do belong to religious groups, tolerance is flourishing among them, too.

The Aunt Susan Effect

One huge factor in that increased tolerance?

A new book by professors Robert Putnam and David Campbell seeks to examine some of the changes.

Not too long ago, such a link between religiosity and political belief was almost unheard of.

And yet the title includes the notion of American unity, which the authors say is a big focus of the book.

The Aunt Susan Effect

One huge factor in that increased tolerance?

The America of today, Campbell says, has "managed to accomplish something that is historically and internationally unique — that we're a religiously devout country, a religiously diverse country and a pretty religiously tolerant country."

"How frequently you attend church, or interestingly, how frequently you say Grace ... measures like that, how religious you are, have a pretty strong correlation with how you vote and which party you prefer," Campbell says.

Unsurprisingly, American Grace points to a current correlation of more religious people with the Republican Party (though Putnam points out that African-Americans are an important exception to the rule).

The Aunt Susan Effect

One huge factor in that increased tolerance?

A new book by professors Robert Putnam and David Campbell seeks to examine some of the changes.