A couple of days ago, WaPo’s Lisa Miller drew a curious lesson from the Iowa caucus results. 

The most interesting poll data from the Iowa caucuses are these: Mitt Romney won in the cities. Rick Santorum
won in the rural areas. In Iowa, where the vast majority of voters
qualify as “white evangelicals,” these results can only mean one thing.
Conservative Christians who reside in urban areas may have been taught
in Sunday school that the Church of Jesus Christ of Latter-day Saints is
a heretical sect, but they’re willing to look beyond those teachings
and cast a vote for a Mormon who was once pro-choice. Their brothers and
sisters who reside in the country are not. Because nearly 80 percent of
Americans live in or near cities, that’s very good news for Romney.

This is, not to put too fine a point on it, nonsense. For starters, the vast majority of voters in Iowa do not qualify as white evangelicals. In the 2008 general election, the state exit poll showed that only 31 percent of Iowa voters so identified. Of course, they constitute a much higher percentage of Republican voters–57 percent in last week’s caucuses.

But these folks are not evenly distributed across the state. Using the interactive database of the North American Religion Atlas, it’s possible to estimate the proportion of evangelicals county by county according to the strength of different religious bodies. Thus in Sioux County, where Santorum got 46 percent of the vote to Romney’s 14 percent, roughly 50 percent of the entire adult population is evangelical. But in Polk County (Des Moines), where Romney won with 28 percent of the vote to Santorum’s 22 percent, evangelicals constitute about 15 percent of the population.

In other words, Romney won the cities because the cities have fewer evangelicals, not because urban evangelicals are more accepting of religious “others.” The big picture, as I noted earlier, is that Romney’s proportion of the evangelical vote in the Iowa caucuses dropped by nearly one-third from 19 percent to 14 percent, between 2008 to 2012. There’s no way to turn that into good news for him.