From its beginnings as a home for English religious dissidents, the United States has made morality a matter of public policy. In his book "Hellfire Nation: the Politics of Sin in American History," James Morone traced the Puritans' influence through three centuries, and found that the Puritan impulse has made itself felt in surprising ways. He shared some of that history in a recent interview with Culture producer Paul O'Donnell

You trace the politics of sin in America back to the founding of the nation by the Puritans.
A great metaphor for the United States is this mythic moment when the Puritans arrive and face the great existential question of who they are, and they define themselves in good, Calvinist terms as the community of saints preordained for salvation.

That metaphor is coupled with two others. First, we're a city on a hill, the eyes of all people upon us. Second, we're an open door. Any stranger for most of the history of America can come ashore. The notion that we're essentially good people, combined with a providential mission to show the world what a good society is like, plus the constant influx of new people. Those three things make a wonderful hook for seeing America in a way we haven't understood.

Were the Puritans really what we think?
There are two sides to the Puritans. One side was the prime imperative, "Control Thyself"--don't give in to the lusts of the flesh. Yet there was also a communal idea that you were responsible for one another. It was the community God was going to judge, and it was every members' job to make sure the whole community was good and that it prospered.

These two strands--the worry about misbehavior, and the worry about other people generally--emerge out of the Puritan psyche and wrestle for control of American politics. The best moments for both liberals and conservatives have been faith-based moments.

How do we see the two strains today?
It's a continuum, but the religious right has grabbed onto one strain, and used it very powerfully. Their idea is that our common troubles flow from individual misbehavior. We're only as good as the individuals who make up the nation, and if the individuals don't behave, then social trouble follows. The great temperance movements, the drug war, the crime war really flow from that Puritan idea.

The other side says our individual troubles come from problems with the political, social and economic system. I call this the Social Gospel, plucking that term out of its historical occurrence in the early 20th century and using it to describe this whole alternative political morality. This idea came on at the turn of the century with Walter Rauschenbush and Jane Addams and reached its highpoint with Martin Luther King. Their great social reforms come from this Social Gospel strain.

So on one side a preacher comes along and says if we don't stop drinking, America is doomed. That's the individual, rightist Puritan tradition. On the other side, along comes the abolitionist, who says our great sin has nothing to do with slaveholders; it's in the system of slaveholding. Both are vibrant tradition.

Sin sounds like a concern of the religious right, but you point out that the left is just as prone to adopt the metaphor of sin.
The left was as moral in the Sixties as the right is today. They said capitalism led people to behave immorally. Certainly they thought segregation, as a set of laws, was immoral. Vietnam was immoral as a policy. If you wanted to smoke, drink, do pot--the sins that drove Victorians nuts--they didn't care about those. They looked at the larger system.

But as your section on the Welfare Reform Act shows, conservative politicians have begun to attack the system as well.
Both sides want to reform public policy. But the right's public policy is driven by a need to make individuals moral. The great preacher of this point of view is Ronald Reagan. He changed the rhetoric of American politics. Again and again, his diagnosis of the problem was individuals--you might even say individual sinners. Drug problem? Just say no. Crime problem? Lock 'em up. Welfare problem? Make people responsible. Even if your approach is to change the system, the goal is to make individuals behave.

Morality has become an important part of the Republican coalition. Since the early 70s, liberals have run from moral politics. Perhaps the '60s were too hot, or too crazy, or perhaps Roe v. Wade redefined liberal politics. But the left has dropped its old moral vision just as the conservatives have embraced it. That's crucual to understanding, not just the growing Republican majority, but its tone, with this powerful call to arms on radio and TV and from a thousand pulpits.

How did Roe v. Wade effect the liberal stance?Since Roe v. Wade, many liberals say politics and morals should be divorced. People's private lives are their own private lives. Historically, however, both left and right have found their poltical dynamite in moral movements. Look at civil rights, abolition--they had a moral fervor about them. Giving it up might make a lot of sense in intellectual sense, but it really puts the left at a disadvantage.