Here's an interesting article from Beliefnet that analyzes the demographics of religious voters and their role in the last Presidential election. Beliefnet's surprising conclusion is that the Religious Left was almost as active and decisive a force as the Religious Right. According to their statistics, both groups are roughly 15 to 17 percent of the populace (for exact figures, just surf on over to the article).
The Religious Right was a slightly larger group, but not by that much. Where Bush really gained strength was with a group that the article called "The Heartland Cultural Warriors." These are traditional, Mainline Protestants and Roman Catholics who voted for Bush based on the abortion and gay marriage issues. Although they are not Evangelicals, they consider cultural issues the most important ones and voted accordingly.
However, the Democrats have a good block of Religious Leftists, which includes Latinos, Black Protestants, and non-Christian members of minority religions such as Judaism, Islam, Hindusism, and Buddhism. Probably more work could be done to mobilize this base.
There are also Mainline Protestants, Liberal Catholics, and even a small percentage of Evangelical Protestants who voted Democratic. They identified the economy or foreign policy as their most important issues.
I would guess that in the next election, the Democrats could peel off a portion of the Heartlanders by avoiding some of the culture war baggage and, even more importantly, stressing the economy not just as an issue of self-interest, but by framing it in moral terms. It isn't, after all, just about the individual voters economic well-being, it is also a social justice issue.
Democrats need to compete for religious voters in the morality and values arena by stressing the social justice and environmental stewardship themes. The truth is the Democrats are never, never going to get that segment of the Religious Right that identifies abortion and gay marriage as their most important issues. They shouldn't even try. Some groups just arent' our consituency.
But that does not mean Democrats should turn their back on all people of faith. There is a Religious Left and it is alive and well and waiting for a political party to stand for social justice, world peace, respect for diversity, care of the environment, and compassionate family values that include help for working mothers, support for families of gay people, and assistance to end poverty and HIV/AIDS.
There are people out there waiting for the Democrats to frame their platform in the moral language of faith. And I am one of them.