Steven Waldman, editor in chief of Beliefnet, offers a survey of the religious left at Slate.com. He divides the left into five groups: “Bible-thumping liberals,” “pious peaceniks,” “ethnic churchgoers,” “conflicted Catholics,” and and “religious feminists.” Here’s how he describes each group:

The Bible-thumping liberals:

The most important leaders of the Bible-thumping liberals are Jim Wallis and Tony Campolo. Both sharply disagree with the Democratic orthodoxy in favor of removing religion from the public square. Wallis, Campolo, and their supporters like politicians who cast their policies in religious terms–for instance, by reminding us that the Bible urges a fight against poverty. As Wallis wrote, “[M]any of the most progressive social movements in American history–anti-slavery, women’s suffrage, the fight for child labor laws and the civil rights movement–had overt religious roots and motivations.” In some cases, the Bible-thumping liberals are pro-life; in other cases they support legalized abortion but want to reduce the number of abortions.

The Pious Peaceniks:

This group is composed of white liberal Protestants, Catholics, Reform Jews, and an occasional Buddhist. Its members are carrying on the spirit of the anti-war movement of the 1960s and 1970s and the nuclear freeze movement of the 1980s. They have mobilized in opposition to the Iraq war and have a strong interest in environmentalism and antagonism toward corporate America. . . . Along with Bible-thumping liberals, the peaceniks joined and helped lead the effort to derail strict immigration reform. Unlike the Bible-thumpers, they tend to align almost down the line with secular liberals. They were, for instance, suspicious of Clinton’s New Democrat philosophy, especially its emphasis on welfare reform and crime fighting, which they thought demonized the poor and minorities. And they tend to be pro-choice or silent on abortion.

The Ethnic Churchgoers:

In this group are African-Americans, Hispanics, and Muslims, who together accounted for about 19 percent of the Kerry vote in 2004. Though they also opposed the Iraq war and share the views of other religious lefties about the importance of fighting poverty and protecting the environment, they differ from the other groups on abortion and, even more so, gay rights. Sixty-four percent of African-Americans oppose gay marriage. . . . Hispanic Christians shifted significantly to Bush during this election. If that trend persists, it will make the Democrats the minority party for decades. . . . Like blacks and Hispanics, Muslims often like Republican values on social issues but look to Democrats to defend their civil rights.

The Conflicted Catholics:

Liberal Catholics are like liberal Protestants and Jews on poverty, war, and the environment. Slight differences arise around gay marriage and abortion. Though more pro-choice than Hispanics or blacks, liberal Catholics tend to feel guiltier about abortion. The real difference may not be in the policies they support–the majority want abortions to be legal but restricted, just like the majority of the rest of the population–but in their attitudes toward pro-life people. Liberal Catholics are less likely than secular liberals to hold pro-lifers in contempt. Even if they disagree with church theology and skip Mass, their religious background makes them respect the heartfelt nature of the anti-abortion position.

The Religious Feminists:

This is perhaps the newest faction. In aiming to win for women the right to control their own bodies, feminism ran up against the patriarchy of many religious institutions. Some feminists, however see spirituality as an important part of their lives and have begun trying to bring faith into their movement.

Interstingly, Waldman points to abortion as the key issue, arguing that this issue complicates the ability of the political left to hold feminists and Catholic voters together in a unified coalition. As he remarks concerning Catholic voters: To frame abortion for this group, Democrats at least need to pretend that they want to reduce the number of abortions. And even as they fight to keep abortion legal, the Dems shouldn’t mock pro-life advocates as sexually repressed theocrats or describe abortion as merely a surgical procedure.

Pretend that they want to reduce the number of abortions? So much for taking a principled position.

Waldman’s conclusion is that the religious left is now more unified by opposition to the war in Iraq and immigration restrictions than divided by abortion and gay marriage. Time will tell, but Waldman’s typology is worth a look.