NPR had an interesting item Sunday morning about religion and politics. What jumped out at me is what John Green was quoted as saying. During the 1972 presidential campaign, George McGovern's young liberal activist supporters tended to be more secular than the average voter. Green says,

The secular activists were very adamant and zealous about their particular issues and pushed very hard for the Democratic Party to adopt liberal positions on social issues. A very similar thing happens in the Republican Party, where the zealous activists of the religious right pushed very hard for the GOP to adopt conservative positions on social issues.

Moreover, he says,

The traditionally religious tend to find morality in personal terms, a personal misbehavior or sexual conduct, the personal treatment of other people. On the other hand, less traditional religious people tend to think of morality in broader, more macro terms; a question such as the structure of society, the distribution of income, of the status of war and peace between nations. So it's not that we have a moral group opposing an immoral group, but rather we have a disagreement about how to think about morality.

However, it's probably easy to exaggerated the importance of this. For instance, I'm un- or even anti-religious, but I still think of morality in personal terms. And it certainly doesn't mean that the Democratic Party is the party of secularlists, while the Republicans are all religious. As Steven Waldman writes,

People often confuse the words "fundamentalist" and "evangelical." Fundamentalists are very conservative and almost entirely Republican because they view the deterioration of traditional morality as the primary public policy crisis. But fundamentalists are a subset of evangelicals, which is a more diverse group.

He also links to the Pew Religion Forum study, which says that fully half of of Americans say they would not vote for a well-qualified atheist.