If you’re not religious yourself, and derive your impressions of Christianity in this country from the news media and the shouting of self-appointed Prophets, you’d be excused for thinking that Christians are pretty much all divided into Catholics and conservative evangelical Protestants. Sure, you might be dimly aware that there was once a large group of people called Mainline Protestants, but they’re a relic of the past, decimated by their wishy-washy liberalism and reluctance to leap into politics to defend infallible truths.
But despite many predictions by both secularists and religious conservatives that they are a dying breed, the fact is that Mainline Denominations (as measured by affiliation with that quintessential “liberal” institution, the National Council of Churches) represent 45 million Americans, which is a lot more than a few. They’re a diverse group, to be sure, including denominations like the Eastern Orthodox churches which are quite conservative on many cultural issues. But by and large, they have dissented conspicuously from the Christian Right movement, and its alliance with conservative politicians.
According to a new analysis from Beliefnet’s Steve Waldman, this election cycle may represent something of a watershed for Mainliners, particularly those “whitebread” Protestants (the original WASPs) who have had an attachment to the Republican Party that goes right back to the Civil War and the Prohibition movement.
Here’s Waldman on the subject:

This used to be a solidly Republican group. In 2004, they went for President George W. Bush 54%-46%. This summer, John McCain was leading Sen. Obama among these voters 43% to 40%, according to a study by John Green of the University of Akron.
But an ABCNews/Washington Post poll released Monday showed Sen. Obama now leading among Mainliners 53%-44%, indicating that the undecided voters are breaking heavily for the Democratic candidate.
Why? The superficial answer is, as with so many other questions, the economy. In Beliefnet’s Twelve Tribes study, 68% of centrist Mainliners (what we called “White Bread Protestants”) said the economy was the No. 1 issue compared with just 4% who said social issues….
The Mainline shift to Sen. Obama may be partly an unintended consequence of Sen. McCain’s efforts to energize evangelical Christians, including through the selection of Alaska Gov. Sarah Palin. Though fiscally conservative, mainline Protestants are socially liberal – so they would be unimpressed by the Republican Party adopting the most antiabortion platform ever. Mainliners may be irritated or scared by Gov. Palin’s religious language and beliefs – including her attendance at a Pentecostal church espousing “End Times” theology (that we’re approaching the end of the world and Christ’s return).
In general, Mainliners have grown increasingly uncomfortable with the role the “religious right” has played in the Republican Party. According to a new survey by a progressive group called Faith in Public Life, Mainliners – by a margin of two to one — believe public officials are too close to religious leaders. Evangelicals, by a two to one margin, think politicians should pay more attention to religion.

For a long time, the GOP was able to count on the residual loyalty of Mainline Protestants while devoting virtually all of its religious outreach to conservative evangelicals and “traditionalist” Catholics. But shirking these Mainline believers, while allying themselves with religious spokesmen who frequently speak of Mainliners as little more than pagans who like singing hymns, is a gamble that has finally caught up with the Republican Party. And this backlash has not been helfpul to John McCain, a Mainline Episcopalian by birth who now calls himself a Southern Baptist.