[Warren Goldstein is a professor and chairman of history at the University of Hartford. He is the author of William Sloane Coffin Jr.: A Holy Impatience (Yale University Press, 2004).]

... A few months ago, a UCC [United Church of Christ] church near where I live was sponsoring a Lenten lecture on liberal Protestantism. My wife, a UCC minister who could not attend, thought it would be good for me to get out of the house and find out what someone else thought for a change. The lecturer, a bright young historian, also married to a minister, professorially explained the origins of the movement in German biblical criticism, continued with a description of the pre-World War I Social Gospel, followed up with the postwar disillusionment and decline, and then simply stopped, observing that liberal Protestantism had been on a downward slope ever since. No Reinhold Niebuhr, no Martin Luther King Jr., no civil-rights or antiwar movement, nothing on the fight for women's rights or gay rights. Far more telling, no members of the audience -- including many senior citizens who had lived through the turmoil of the latter 20th century -- objected to their entire religious lives' being considered unworthy of academic notice. I hope they were being polite, but I suspect that their apathy was a symptom.

Indeed, the liberalism of mainline Protestantism appears to be suffering a fate similar to that of liberalism in today's world of politics. Since the presidency of Ronald Reagan, the leaders of the Democratic Party, once the home of a proud and unapologetic liberalism, have successfully hidden their liberal light under a bushel of apologies and strategies for impersonating Republicans. Now, beaten twice in narrow national elections, apparently by religious conservatives, some Democrats are beginning to remember that moral values have power on the left side of the aisle, too. But instead of relying on their own traditions, they are trying to open a dialogue with evangelicals -- witness Senator Hillary Rodham Clinton urging abortion-rights activists to seek common ground with those who oppose abortion.

Since I'm no political strategist, I have no idea if that will work. I am, though, a historian who has written on William Sloane Coffin Jr. and the liberal tradition he brought to the chaplaincy at Yale University in the 1960s and 1970s, which fired the faith and activism of a generation still very much alive. And so I wonder whether the folks formerly known as liberal Protestants and their colleagues and counterparts among liberal politicians might gain some inspiration from the accomplishments of their own histories before giving up on what they might bring to the future.

Much 20th-century American political history was the history of liberalism. From Progressivism in the early years of the century to the almost 50 years stretching from the inauguration of President Franklin D. Roosevelt through that of Ronald Reagan, political and economic liberalism set the terms of public debate and public policy. It had blind spots and nasty habits, of course, most notably racism and an unfortunate faith in imperial ventures abroad. But when white people did finally begin taking race seriously, and mainstream Americans turned against the war in Vietnam, liberals and progressives led those charges.

What tends to be forgotten is that they did so not just through political parties or movements. The Social Gospel's commitment to improving conditions in society according to Christian principles supported much of early-20th-century Progressive reform; Harry Emerson Fosdick, America's most eminent preacher of the 1930s, began his career as a Social Gospeler who attacked fundamentalism and embraced pacifism. Over the space of five decades, Niebuhr, the most influential American theologian of the 20th century, first defended the working class on religious grounds, then criticized capitalism and what he saw as the timidity of the New Deal, and later inspired a generation of liberal cold warriors. The explosion of theological liberalism and the ecumenical movement after Vatican II (1962-65) provided religious fuel, language, and fervor for the civil-rights and antiwar movements.

Take the Social Gospel, later to be maligned by Niebuhr as naïvely progressive, too trusting in the perfectibility of human beings, too eager to locate the source of sin in social structures rather than the individual. In fact, most of those traits it shared with secular Progressivism, along with a casual belief in Anglo-Saxon superiority, imperial paternalism, Prohibition, and support for the crusade of World War I. But as preached and put into practice by the Congregational minister Washington Gladden, the Baptist Walter Rauschenbusch, and many others, the Social Gospel was no minor movement. A prolific author and champion of the "historical critical" approach to the Bible, Gladden served a parish in Columbus, Ohio, for 30 years, where he spoke out on behalf of workers' rights during a Cleveland streetcar strike in 1886 and actively supported a whole range of Progressive causes, including compulsory arbitration and women's suffrage....

Even in the 1970s, as the wind went out of political liberalism's sails, and in the 1980s, when the "Reagan revolution" made political liberalism into the "L-word" and brought the religious right to public prominence, mainline liberal Protestantism, with important Catholic and Jewish allies, continued to speak out on behalf of the poor at home and the oppressed abroad. As Ronald Reagan rewrote the tax code, slashed social programs, and began the largest peacetime military buildup in U.S. history, it was religious institutions that housed and nurtured liberal dissent. [William Sloane] Coffin, who had gone to Riverside Church as senior minister in 1977, turned Fosdick's flagship into a key international institution of the left. Coffin himself provided articulate leadership and organizational resources for the movement opposing U.S. intervention in Central America, for the rights of gay and lesbian people, for anti-apartheid organizing, and, most of all, for the nuclear-disarmament movement. Without the Riverside Church Disarmament Program, founded by Coffin, it is unlikely that the largest demonstration in American history, on June 12, 1982, would ever have taken place....