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In 1860, in the midst of the tensions surrounding the Civil War, it was widely believed in the United States that Abraham Lincoln was Catholic. Coming on the heels of decades of anti-Catholic sentiment, the rumors seem to have had two roots: The first was the ambiguous nature of Lincoln’s upbringing in Illinois, where Jesuits were very active, leading to the notion that Lincoln had been baptized a Catholic; the other was that Lincoln represented a prominent critic of the Church. The rumors were widely repeated by Lincoln’s political opponents.

In 1940, in the midst of tensions surrounding World War II as well as economic hardship from the Great Depression, it was widely believed in the United States that Franklin Roosevelt was Jewish. Coming on the heels of decades of anti-Jewish sentiment, the rumors seem to have had several roots: The first was the ambiguous origins of Roosevelt’s earliest American ancestors, who came from Holland in the 17th century; the second was the abundance of Jewish appointees to Roosevelt’s administrations in New York and Washington. The rumors were widely repeated by Roosevelt’s political opponents.

In 2010, in the midst of tensions surrounding wars in Iraq and Afghanistan as well as economic hardship from the Great Recession, it is widely believed in the United States that Barack Obama is Muslim. Coming on the heels of decades of anti-Muslim sentiment, the rumors seem to have had several roots: The first is the ambiguous nature of Obama’s upbringing, in which his father was a Muslim and he spent formative time as a child in a Muslim country; the second is his political outreach to the Muslim world and his support of the rights of Muslim-Americans. The rumors have been widely repeated by Obama’s political opponents.

Perhaps the most surprising thing about the news this week that 1 in 5 Americans believe Barack Obama is Muslim is that so many people greeted the news as a surprise. Americans taking out their discrimination toward minority religions on the president of the United States is as American as apple pie; the custom has been going on as long as there has been a presidency. George Washington was the subject of widespread grumbling that he was a more loyal Mason than he was a Christian.

The entire debate about the “Ground Zero mosque” and the even-wider campaign against Islam in general that’s been waged across the United States this summer misses a larger point: These kinds of campaigns have been waged in the United States since our founding. It’s the nature of how we conflate political frustration, economic anxiety, and concern about the changing fabric of our identity. In a country where our national character has been tied up with God since our founding, it’s hardly surprising that we tar our political opponents with worshiping a different god than we do. After all, a politician who subscribes to our religious values would never have gotten us into this mess, now would he?

But as reliably as Americans have adopted these views, they’ve also moved past them. In every case of religious discrimination in the United States, whether it was Methodists in the 18th century, Catholics in the 19th century, or Jews in the 20th century, the once reviled and ostracized “outsider” religion in America eventually makes it into the inner circle.

And odds are the pattern will repeat itself with Muslims in the 21st century.

Bruce Feiler is the author of five New York Times bestseller, including "WALKING THE BIBLE:  A Journey By Land Through the Five Books of Moses" and "AMERICA’S PROPHET:  How the Story of Moses Shaped America," which will be released in paperback next month.

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