Democrats are making a play this week for those "values voters" whose faith shapes their politics. The Denver convention is the site for faith caucuses, debates about morality and discussions about how an Obama administration would impact religion.Some party secularists may not like that, but they do want to win. And they have a new opening among religiously minded voters, for which they can thank Barack Obama and Karl Rove.

Like Jimmy Carter and Bill Clinton, Mr. Obama speaks naturally about his personal faith and the public dimension of religion, comfortable in a way John Kerry never was.

That shows in his campaign. William Galston of the Brookings Institution describes the Obama campaign's outreach to religious voters as "night and day" different from the Kerry campaign.

True, Mr. Obama trails significantly among evangelicals in polling, but it's revealing that he isn't conceding any religious group. If he were, you wouldn't have seen him at Rick Warren's recent Saddleback Church forum.

Democrats wouldn't have this opening if Republicans hadn't misplayed their hand with religious voters. Mr. Rove's strategy of playing to the most conservative evangelicals actually created a backlash among other values voters.

Look at the survey released this summer from Calvin College's Paul B. Henry Institute for the Study of Christianity and Politics. It shows mainline Protestants – about 16 percent of the voting population – are moving to the Democrats in surprising numbers.

Only eight years ago, 50 percent of mainline Protestants (Methodists, Presbyterians, Episcopalians, etc.) considered themselves Republican, while only 32 percent identified as Democrats. Now, after eight years of the Bush-base strategy, the numbers have flipped. Forty-six percent of mainliners consider themselves Democrats and only 37 percent Republicans.

This flip is pronounced among mainliners who consider themselves moderates in religious practice and theology. Four years ago, 46 percent of centrist Protestants identified as Republicans, only 33 percent as Democrats.

Today, it's 52 percent Democrat and 28 percent Republican.

These are significant changes. Mainline Protestants once were the backbone of the GOP, like chamber of commerce members. As recently as 1992, they voted Republican more reliably than even white evangelicals.

Why the shift? Bush policies, in part. The intense focus on cultural issues like abortion and gay marriage has driven some in search of an alternative view of religion-in-politics. Calvin's Douglas Koopman told me he and his fellow researchers saw this as particularly true among younger voters.

This data also highlights the fundamental mistake in Rove-ism. You can't pursue a course of action without producing a reaction. In this case, the Bush administration couldn't play to the most loyal conservatives on abortion or even the environment without spawning a reaction among others.

So, welcome to Denver and the Democratic opportunity.

Democrats are smarter now. For too long, they ignored religious voters, as Perkins School of Theology Dean William Lawrence says in this week's "Texas Faith" discussion at dallasnews.com/texasfaith.

The question is whether Mr. Obama can bring home these disaffected Republicans. He must offer something more than not being President Bush, and there's no guarantee he can do that.

Mr. Obama's accommodating style makes people think he can bring Americans together. But at some point, he has to start being clear about where he stands on issues that matter to religious-minded voters. Evasive answers like the one he gave at Saddleback about when life begins – "That's above my pay grade" – will lead some in the values camp to believe he's messing with them.

This is the Obama dilemma, which even some Obama supporters I interviewed acknowledge. He sounds good, but where does he really stand?

Sooner than later, details will matter. As they say, to govern is to choose.

William McKenzie is a Dallas Morning News editorial columnist and a moderator of Texas Faith at www.dallasnews.com/texasfaith. His e-mail address is wmckenzie@dallasnews.com.

To participate in an online discussion with Texas clergy, laity and theologians about Democrats and religion, visit our new Texas Faith blog.