Three and a half years into the presidency of Barack Obama, 17 percent of registered voters still believe that he is a Muslim despite the fact that he is a Christian, according to a poll released Thursday by the Pew Forum on Religion and Public Life. Forty-nine percent correctly identified that he is a Christian, while 31 percent of respondents said they did not know.

The poll showed a striking increase in Republicans and conservative Republicans who say that Obama's Muslim. Sixteen percent of both groups in October 2008 said that he was Muslim, while in this survey, 30 percent of Republicans and 34 percent of conservative Republicans said so.

More Americans than in 2010, however, correctly said that Obama is a Christian. But the percentage is still down from 2008, when 55 percent identified him as such.

Those who said that he is a Christian were more comfortable with his religion than those who said he is Muslim -- 82 percent were comfortable among those who said he is a Christian, while 65 percent were uncomfortable among those who identified him as a Muslim.

Obama broke with his controversial pastor Jeremiah Wright during the 2008 elections after incendiary video clips of Wright's sermons surfaced. Obama has attended several churches in the Washington, D.C. area.

More respondents know that Mitt Romney is Mormon. Sixty percent of the Pew poll's respondents correctly identified his religion, while 9 percent said "other" and 31 percent didn't know. Sixty percent of those who said he was a Mormon were comfortable with his religion, 21 percent didn't care and 19 percent were uncomfortable.

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  • Osama Bin Laden Killed -- "Tonight, Tonight"

    <a href="http://www.huffingtonpost.com/2011/05/01/osama-bin-laden-dead-killed_n_856091.html" target="_hplink"><strong>(May 1, 2011)</strong></a> -- In a televised address to the nation, Obama announces that Osama bin Laden is dead. His death was the result of a U.S. operation launched today in Abbottabad, Pakistan, against a compound where bin Laden was believed to be hiding. "[T]oday's achievement is a testament to the greatness of our country and the determination of the American people," Obama proclaimed. (Photo by Pete Souza/The White House via Getty Images)

  • Debt Ceiling Deal -- "Gold On The Ceiling"

    <a href="http://www.huffingtonpost.com/2011/08/02/obama-debt-ceiling-deal-jobs_n_916285.html" target="_hplink"><strong>(Aug. 2, 2011) --</strong></a> After the Senate passed a bill to raise the debt limit, Obama pleaded with Congress to shift their attention to jobs. "I will urge them to immediately take some steps -- bipartisan, common-sense steps -- that will make a difference; that will create a climate where businesses can hire, where folks have more money in their pockets to spend, where people who are out of work can find good jobs," he said. (Photo by Brendan Smialowski/Getty Images)

  • Don't Ask Don't Tell -- "Don't Stop Believin'"

    <a href="http://www.huffingtonpost.com/2011/09/20/barack-obama-dont-ask-dont-tell-repeal-statement_n_971662.html" target="_hplink"><strong>(Sept. 20, 2011) --</strong></a> As the ban on gays serving in the military came to an end, Obama hailed the fresh start, celebrating the fact that "patriotic Americans in uniform will no longer have to lie about who they are in order to serve the country they love." (Photo by Brendan Hoffman/Getty Images)

  • Iraq War To End -- "Homeward Bound"

    <a href="http://www.huffingtonpost.com/2011/10/21/obama-iraq-troop-withdrawal_n_1024108.html" target="_hplink"><strong>(Oct. 21, 2011) --</strong></a> Obama announced that all U.S. troops will be out of Iraq by 2011, fulfilling a promise that dated back to his campaign. "As a candidate for president, I pledged to bring the war in Iraq to a responsible end," Obama said. "So today I can report that, as promised, the rest of our troops in Iraq will come home by the end of the year." (Photo credit should read JIM WATSON/AFP/Getty Images)

  • Singing Al Green's "Let's Stay Together"

    <a href="http://www.huffingtonpost.com/2012/01/20/obama-al-green-apollo-theater_n_1218070.html" target="_hplink"><strong>(Jan. 20, 2012) --</strong></a> During a fundraiser at Harlem's historic Apollo Theater, Obama delivered a memorable musical message to his donors. With Rev. Al Green in attendance, Obama sang part of Green's hit song "Let's Stay Together," drawing strong applause from the crowd.

  • Singing Robert Johnson's "Sweet Home Chicago"

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  • Health Care Reform -- "Beautiful Day"

    <a href="http://www.huffingtonpost.com/2012/06/28/supreme-court-health-care-decision_n_1585131.html" target="_hplink"><strong>(June 28, 2012) --</strong></a> After weeks of speculation that Obama's signature piece of legislation could be overturned, the Supreme Court ruled that the Affordable Care Act's individual mandate is constitutional. "It should be pretty clear that I didn't do this because it's good politics," <a href="http://www.huffingtonpost.com/2012/06/28/obama-health-care-ruling_n_1632953.html" target="_hplink">Obama said</a>. "I did it because it's good for the country." (Photo by Alex Wong/Getty Images)