Post-election reporting that 79 percent of white evangelicals voted for Mitt Romney got little attention in the news because most journalists thought it wasn’t news. Evangelical support for the GOP has been consistent; even Romney’s Mormonism didn’t put them off. So election analysis approached white evangelicals as it usually has: as religio-political lemmings, all voting Republican for all the same reasons.

Yet where there was once the appearance of a monovocal evangelicalism there is now robust polyphony—what theologian Scot McKnight calls “the biggest change in the evangelical movement at the end of the twentieth century, a new kind of Christian social conscience.” This deserves our attention because most politics does not happen at elections but in...