Over half of Republicans answered "Muslim" when asked which religion describes President Obama's "deep down" beliefs, according to a newly released poll by Alex Theodoridis of the University of California at Merced.

Theodoridis, who released the results on Wednesday on the Washington Post political science blog Monkey Cage, asked Americans this question: "Which of these do you think most likely describes what Obama believes deep down? Muslim, Christian, atheist, spiritual, or I don't know." The poll was conducted in the fall of 2014.

The results, divided by party affiliation, are shown above. And they're pretty staggering. Among Republicans, 54 percent answered "Muslim" when asked what Obama believes; only nine percent said "Christian," his stated religion.

Identifying Obama as affiliated with Islam is not unique to Republicans, according to the poll, which found that 10 percent of Democrats and 26 percent of Independents answered "Muslim" as well. Democrats' most frequent answer was "Christian," with 45 percent.

"I don't know" was also a very popular answer, given by 47 percent of Independents, 26 percent of Democrats, and 19 percent of Republicans. As Theodoridis points out, this is the answer that Wisconsin Governor Scott Walker, a Republican and possible presidential candidate, gave when asked to identify Obama's religion.

The idea that Obama is Muslim, a thread of the "birther" conspiracy theory that Obama is not actually American, goes back to the 2008 presidential campaign, when some Obama critics presented him as "other," if not explicitly foreign.

Still, this poll shows unusually high levels of belief in the idea that Obama is affiliated with Islam. Theodoridis links, for example, to an August 2010 Pew poll showing 31 percent of Republicans identifying Obama as Muslim. A June 2012 Gallup poll reported 18 percent.

Theodoridis suggests that the way his question was phrased likely explains the disparity — and may in fact better portray Americans' views:

Previous survey questions about Obama's religion tend to sound like a pop quiz - such as "do you happen to know the religious faith of Barack Obama?" But by asking "what Obama believes deep down?" I was intentionally granting respondents license to stray from the president's self-reported Christian faith. This reveals a prevalent willingness to distrust this president or categorize him as "the other" in terms of religion.

The uptick in American, and particularly Republican, views of Obama as Muslim may also in part be explained by the rise of ISIS, which political opponents have seized on to argue that Obama is soft on Islamist terror. While these opponents do not say that Obama is soft on Islamist terror because he is Muslim, they could easily feed into preexisting suspicion of Obama based on his race and background.

In more recent months, Obama has also attempted to defray the tide of American Islamophobia that has coincided with ISIS's rise, in part by correctly defending Islam and Muslims against bigotry. Increased belief that Obama "deep down" believes in Islam may be an unfortunate cost of this effort.

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