The result of the shock and aftershocks is polarization. The general level of religiosity in America hasn't changed much over the years. But, as Putnam says, "more people are very religious and many are not at all." And these beliefs have become "correlated with partisan politics." "There are fewer liberals in the pews and fewer unchurched conservatives."

The political implications are broad. Democrats must galvanize the "nones" while not massively alienating religious voters -- which is precisely what candidate Obama accomplished. Republicans must maintain their base in the pew while appealing to the young -- a task they have not begun to figure out.

But Putnam regards the growth of the "nones" as a spike, not a permanent trend. The young, in general, are not committed secularists. "They are not in church, but they might be if a church weren't like the religious right. ... There are almost certain to be religious entrepreneurs to fill that niche with a moderate evangelical religion, without political overtones."

In the diverse, fluid market of American religion there may be a demand, in other words, for grace, hope and reconciliation -- for a message of compassion and healing that appeals to people of every political background. It would be revolutionary -- but it would not be new.