What do conservative TV and radio personality Glenn Beck and U.S. President Barack Obama have in common? Most U.S. Protestant pastors doubt their Christian credentials.

These are among  the findings of a survey released this week by LifeWay Research, the number-crunching  arm of the Southern Baptist Convention, which sometimes does interesting pastor polls.

The poll in question, of 1,000 U.S. Protestant pastors, asked: “Which, if any, of the following people do you believe are Christians?” It then gave a list of five prominent personalties: TV diva Oprah Winfrey, former U.S. President George W. Bush, Beck, Obama and former Alaska governor and conservative sweetheart Sarah Palin.

USA-POLITICS/RALLY (Photo: Glenn Beck raises his hands to the crowd as he stands on the steps in front of the Lincoln Memorial to address supporters at his Restoring Honor rally on the National Mall in Washington, August 28, 2010/Jonathan Ernst)

Only 27 percent of the respondents said they believed Beck, who is a Mormon, was a Christian and only 41 percent — well less than half — answered in the affirmative regarding Obama. Bush scored the highest at 75 percent and Palin was second at 66 percent. Oprah came in rock bottom at 19 percent. The national telephone survey took place Oct. 7-14.

It all raises some interesting questions and may raise a few eyebrows.

Let’s start with Beck, who often speaks the political and even spiritual language of conservative evangelical Christians– and counts many as his fans – but cannot score theological points with them because of his Mormon faith. Many evangelicals regard The Church of Jesus Christ of Latter-day Saints as an oddball cult and the survey’s results show it may be as much a political liability for Beck the activist as it is for Mitt Romney the candidate, the former and perhaps future Republican presidential contender.