With all eyes on the Buckeye State–which according to Nate Silver has nearly a 50 percent chance of being the tipping point in the Electoral College today–it behooves us to take a look at last look at what's happening to the evangelicals who constitute the state's largest religious voting bloc.

They've been tracked on a weekly basis by SurveyUSA, and when last we checked two weeks ago, there was at least a hint that they might be headed towards voting for Mitt Romney over Barack Obama at close to the 71-27 margin that they voted for John McCain in 2008. But that doesn't seem to be happening.

At the beginning of October, Romney led Obama by just 20 points, 57-37. Two weeks later, the margin was up to 28 points, 60-32. But then last week, it slipped back to 24, 59-34.   Now it's back up to 27, 61-34. If that number holds in the voting today, Romney will poll 13 points worse with evangelicals than McCain did four years ago.

SurveyUSA finds Obama leading Romney overall by five points in Ohio. With evangelicals constituting one-third of Buckeye voters, that 13-point differential thus represents better than a four-point swing in the survey total–accounting for nearly all of Obama's 5-point lead. In other words, if SurveyUSA is on the money, Romney's loss of Ohio will be largely the result of his failure to maintain the GOP's recent hold on its evangelical base