In 2004 the head of the Democratic National Committee, Terry McAuliffe, was introduced to megachurch pastor Rick Warren, author of the mega–best-seller The Purpose Driven Life. McAuliffe stuck out his hand and said, “Nice to meet you, Rick! And what do you do?”

Amy Sullivan tells this story and a good many others to illustrate how clueless Democratic leaders have been about the Christian world, especially the evangelical Christian world. Current DNC chief Howard Dean has committed his own series of blunders: he once derided the Republican Party as the “white Christian party” and later, when trying to connect with evangelicals, declared that Democrats “have an enormous amount in common with the Christian community”—as if, Sullivan comments, Dean was an ambassador “dispatched to liaise with creatures from Planet Christian.”

The notion that Democrats are the party of resolute secularists is widespread, and it is more than a notion. Polls have shown that the more often one goes to church, the less likely one is to vote for a Democrat. In a country where most voters strongly identify with a religious tradition, and where evangelical Protestants and white Catholics together constitute half the electorate, this “God gap” represents a huge electoral liability.

Sullivan, a politics editor at Time, knows from experience that many people become Democrats because of, not despite, their religious beliefs. Her own faith was developed in a Baptist church outside Detroit, and she recalls spending “Friday nights playing a card game called Bible Daughters . . . and Saturday afternoons knocking on doors for Democratic candidates.” Gospel lessons about loving your neighbor led her to the belief “that citizens—and governments—had a moral obligation to take care of the poor, the sick, the marginalized”—led her, in short, to Democratic-style politics. So how did a God gap emerge?

Part of the answer, of course, is that Republicans in the 1980s made a strategic alliance with the burgeoning political activism of conservative Protestants and conservative Catholics, who mobilized around the issues of abortion and school prayer and the perceived moral decline of the nation. But another part of the answer—and the burden of Sullivan’s book—is that Democratic leaders fumbled their opportunity to respond. They pushed away potential allies among theologically conservative Christians by accepting the religious right’s assessment that Democrats were secular: they acted as if they didn’t need religious conservatives and didn’t want them.

A major case in point is abortion. Sullivan observes that in the 1980s one could still find prominent Democratic figures—including Al Gore and Jesse Jackson—expressing opposition to abortion. But by the end of the decade, support for abortion rights had become the litmus test of Democratic orthodoxy. Sullivan suggests that if the Democrats had offered a big tent on the issue—as, in practice, the Republicans tended to do—and had made some effort to address the concerns of those with moral qualms about abortion, they would at least have given political cover to the theological conservatives who were not one-issue voters and who were attracted to other parts of the Democratic platform.

Abortion remains a central topic for Sullivan as she brings her chronicle closer to the present. She highlights local races in which Democrats have successfully fielded antiabortion candidates (like Bill Ritter in Colorado), and she touts the strategy of candidates who stress reducing the number of abortions (rather than protecting abortion rights) and thereby offer some chance for common ground with conservatives.

Sullivan’s analysis gives rise to a fascinating hypothetical: What if, over the past 30 years, Democrats had had a pro-life plank while remaining committed to other signature issues, like reforming health care, protecting Social Security and supporting gender and racial equality? Perhaps that kind of Democratic Party would have relegated Republicans to permanent minority status—the direction they seemed headed in the 1960s.

One of the great ironies in the history of the God gap is that the most religious presidents of the past half century—Jimmy Carter and Bill Clinton—were both Democrats. Sullivan devotes a chapter to describing Clinton’s familiarity with the Bible, his knowledge of the American religious scene and his comfort level among evangelicals. All this did not stop the leaders of the religious right from reviling him, but in 1996 Clinton won 32 percent of the white evangelical vote, more than any Democrat since Carter. Sullivan suggests that Clinton’s instinctive understanding of religion, regarded as an oddity by many in his own party, shielded Democrats for eight years from realizing their own ineptitude on the topic.

However much Democrats learn to articulate their religious commitments and seek common ground on issues like abortion, they are not likely to change the voting habits of hard-core religious conservatives. But with the electorate as closely divided as it is, it’s not necessary to convince everybody—all you need to do to have an impact is peel off a percentage of voters. Sullivan thinks this can be done if the Democrats care enough to talk to theological conservatives and take their views seriously.

To some extent Democrats have begun to do just that. In the last section of her book Sullivan profiles recent Democratic candidates who have talked convincingly about faith, and she touts the work of campaign consultants Mara Vanderslice and Eric Sapp of Common Good Strategies, who seek to dissolve evangelical stereotypes about Democrats. This year’s Democratic presidential candidate, Barack Obama, has at times shown a Clinton-like touch for reaching out to evangelicals. Unlike Terry McAuliffe, Obama clearly knows all about Rick Warren—and even counts him as a friend.

It is too soon to declare with the confidence of Sullivan’s subtitle that the God gap is closing. A late-summer national poll showed that the percentage of evangelicals prepared to vote for Obama—24 percent—is no greater than the percentage who voted for John Kerry in 2004. There are signs, however, that Obama might do better among evangelicals in the Midwest, which could make a difference in the election.

A growing number of Americans—to cite yet another poll—think politics would benefit from fewer, not more, appeals to religion. I am inclined to agree. In ordinary circumstances, the explicit linking of political positions to a religious identity tends to corrupt religion and muddy politics. But given that religiosity will remain a significant dimension of American politics, and given the distinct political terrain that the major parties have staked out, it would be healthier if neither party has a lock on religious discourse. And perhaps before religious rhetoric can be toned down, the Democrats have to establish, to use Sullivan’s phrase, a “level praying field.”