These numbers certainly aren't set in stone, and they are bound to change before November. The first harsh months of the campaign, including the controversy surrounding Obama's former pastor, the Rev. Jeremiah Wright, have shaken some Christian voters' early confidence in him. During the past two months, Obama's lead has eroded substantially among nonevangelical, born-again Christians (down 9 percentage points), active Christians (a 20-point drop), Protestants (down 13 points), and Catholics (down 11 points).
When the pre-election advertising campaigns begin this fall—particularly those that emphasize Obama's support for abortion rights—those numbers may continue to drop. "There is a lot of anger toward the Bush administration," says Barna. "But faith-driven voters, in particular, are going back and re-examining their initial choice and trying to figure out if this is really someone whose values they can live with for another four to eight years."