Anti-Mormonism bites Romney in South By Howell Raines, Special to CNN March 15, 2012 -- Updated 1316 GMT (2116 HKT) Mitt Romney's Mormonism was an under-the-radar factor in his poor Alabama and Mississippi showing, says Howell Raines Howell Raines: Romney's Mormonism was under-the-radar issue in Tuesday's primaries He says Ala. governor's backing "most conservative" Santorum was code for religious ally He says in 1980 Christians unified with Catholics over Ronald Reagan, creating a base Raines: Romney's Mormomism less hurtful in run against Obama; South will still go GOP Editor's note: Howell Raines, an Alabama native, is an author and former executive editor of The New York Times. He is working on a novel set during the Civil War. Fairhope, Alabama (CNN) -- The polls and the campaign dialogue aren't much help in assessing the Mormon factor in the Alabama and Mississippi primaries. The distinct feeling on the ground was that it had an impact, leading many evangelical Christians to reject pragmatic arguments to ignore Mitt Romney's Mormonism because of his presumed electability. In a pattern dating back to the single-issue campaigns of the segregation era, discussion of this underground religious division was conducted almost entirely through code words and signals and was mainly missing from public forums and press accounts. Howell Raines The strongest signal came from Alabama Gov. Robert Bentley, who had a political ally reveal election day morning that he was voting for Rick Santorum. The announcement came on the statewide "Rick and Bubba" radio show, described by the Birmingham News as having "broad appeal to evangelical, conservative voters." The news flashed around the state long before the polls closed. Everyone understood what was meant by a subsequent Facebook posting by Bentley, who in the last gubernatorial primary rode the church vote to victory over a better qualified Republican opponent. Bentley said he voted for Santorum because he considered him the "most conservative candidate" in the field. Among two-thirds of Alabama Republicans, that description translates to most-like-us-religiously. Also on election morning, the president of the Baptist-affiliated University of Mobile, Dr. Mark Foley, addressed religious divisions obliquely in a prominent op-ed piece addressed to "persons of faith" in the Mobile Press Register. "Honest interpretations of scripture" among Christians "have formed hard lines that make it hard for us to agree," he wrote. He then endorsed Santorum as the best representative of "American ideals." Few people spoke as candidly as a caller to the popular Paul Finebaum radio show. He noted that President Obama was a congregant of the Rev. Jeremiah Wright and Romney is a Mormon. He concluded "hold your nose" and vote for the lesser of two evils. Bloc voting by evangelicals is a standard feature of Southern Republican politics, and polls show it has also fueled Santorum's rise nationally. Belief blog: Romney stumbles in bible belt Students of the theocratic strain in Southern politics may recall that anti-Catholicism was once a major force in the region's elections. But the fact that both Santorum and Newt Gingrich are Roman Catholic had little impact this time. The South's Republican Christian base vote has been unified since 1980, when Northern urban Catholics and Southern born-agains rallied to Ronald Reagan. Religious or racial prejudice is notoriously hard for pollsters to measure. The National Election Pool found that Gingrich and Santorum together got two-thirds of the evangelical vote in Alabama and Mississippi. Romney got 27% in Alabama and 29% in Mississippi. Those numbers probably reflect the number of establishment Republicans in those states, a group that was notably subdued in the days before the election. Would anti-Mormon feeling in the South hurt Romney in a general election? That's not likely, since about half the Republican voters in Alabama and Mississippi believe Obama is a Muslim. In any event, the Deep South is so much a one-party region that nothing will get the Democratic ticket in the hunt. But in contested states, religion, like race, could be a tilt factor that the press seems reluctant to engage. The opinions expressed in this commentary are solely those of Howell Raines.