PORT FOURCHON, La. -- While claiming he believes President Barack Obama is a Christian, presidential hopeful Newt Gingrich is increasingly connecting Obama to Islam, playing into a commonly held myth in the Republican primary electorate.

The Obama-Muslim myth has been around since the 2008 campaign, attributed in part to his time spent as a youth in Muslim-dominated Indonesia. Gingrich said Friday that it persists because of Obama administration policies such as forcing religious employers to provide contraception coverage in health insurance plans or apologizing when U.S. soldiers in Afghanistan burned Qurans.

“It should bother the president,” the former U.S. House speaker and a Catholic convert said when asked at a news conference whether he was concerned that so many voters continue to believe the falsehood. “Why does the president behave the way that people would think that? You have to ask why would they believe that? It’s not because they’re stupid. It’s because they watch the kind of things I just described to you.

“When you have every bishop in the Catholic Church say this administration’s at war with their religion, you don’t think that has an impact? It doesn’t seem to affect Obama.”

Former U.S. Sen. Rick Santorum of Pennsylvania, a conservative Catholic, has trod similar ground. Politico reported Friday that Santorum, during a radio interview with Sean Hannity, said: “You know, it’s not surprising this president will go down in history here as the president who has embraced radical Islamic groups.”

Former Massachusetts Gov. Mitt Romney has avoided the issue. As a Mormon, he faces a religion problem of his own because many evangelicals do not believe the sect is Christian.

Gingrich, badly trailing in the Republican presidential race, spent the week campaigning across Louisiana ahead of Saturday’s primary. The only states he has won to this point are South Carolina and Georgia, the state he represented in Congress for 20 years. Santorum is far ahead in Louisiana, while Romney is the wide front-runner to secure the nomination.

Barry Hollander, a University of Georgia journalism professor who has studied the Obama-as-Muslim myth, said the people most likely to believe it are very conservative Christians who are already predisposed to dislike Obama.

Gingrich “sees an opening for the wackier of the far extreme side of the party, and he’s looking for the conspiracy buff vote, which makes a certain political sense,” Hollander said. “I can see why he would be playing this card. It is one of his last cards.”

University of Notre Dame professor David Campbell, who studies religion and politics, said such talk could stick to other candidates and damage the Republican Party in the general election, as swing voters recoil from such talk. But that does not appear to bother Gingrich.

“He definitely has a long career of making it clear that he’s not terribly concerned about saying overly incendiary things,” Campbell said.

Gingrich often stresses the “war on religion” idea in speeches and interviews. At a stop Wednesday in Pineville, he declared: “They’re anti-religious unless it’s Islam. This is the heart of the Obama problem, the dilemma he has.”

At a Lake Charles restaurant, Bob Nolan voiced this view on the myth to Gingrich directly.

“I also believe that No. 1, he's a Muslim. No. 2, he's a student of Saul Alinsky ... and I believe that it's his policy to bring this country to its knees and ruin the United States of America,” Nolan said of Obama.

Gingrich avoided the topic of Islam in his reply, saying: “I agree with you about Alinsky. I think he's driven by a radicalism to remake America, and he doesn't frankly care what level of pain it costs the rest of us.”

Alinksy was a liberal community organizer and author of “Rules for Radicals.” Gingrich often cites him as an intellectual forebear for Obama.

Gingrich and his advisers were piqued when the fact that Gingrich did not correct Nolan’s view of Obama’s religion was picked up in news reports.

Gingrich spokesman R.C. Hammond said Gingrich often says the president is Christian, and he didn’t correct the questioner on Wednesday because “you can’t pick a fight with everybody.”

Gingrich, asked about the incident that night by Fox News host Greta van Susteren, said the story was “baloney” and added: “I don’t have an obligation to go around and correct every voter on every topic. I also disagree with him.”

During the 2008 campaign, Obama and the news media aggressively rebutted the Obama-Muslim myth. Obama was part of a United Church of Christ congregation in Chicago for year, and he now occasionally attends Christian churches in the Washington area.

Hollander said that nationally between 20 percent and 25 percent of Americans have believed the myth since 2008. Public Policy Polling this month found that among GOP primary voters, 52 percent in Mississippi and 45 percent in Alabama identified Obama’s religion as Islam.

Hollander said most politicians trying to court such voters will not directly call Obama a Muslim but hint at it in a way that affirms the view.

"They’ll say it in such a way as people can read into it what they want to read into it," Hollander said. "What Gingrich is doing is connecting lots of different dots that honestly don’t have a lot to do with one another, but he’s trying to write a narrative about the war on religion."