Religious experts and historians say: all of the above.
The still-unfolding controversy over plans to build an Islamic center near ground zero is just the latest chapter in a long saga of religious and ethnic misunderstanding that experts say goes back to the nation's earliest days.
Fear of foreigners dates to the Alien and Sedition Acts of 1798, which were aimed at French immigrants suspected of disloyalty, said American University historian Allan Lichtman. "Then it was the Irish, the Germans, and the Catholics, and the Jews," he said. "These waves of xenophobia are as American as apple pie unfortunately."
Despite the appeal of blaming the overheated rhetoric over the dispute in lower Manhattan on the still raw emotions left over from the Sept. 11 attacks, antipathy toward Muslims predates the furor around the proposed Park51 Islamic center.
A Gallup Poll conducted late last year found 43 percent of Americans admit to feeling some prejudice toward followers of Islam. That's more than twice the number who feel that way about Christians, Jews or Buddhists.
Acts of vandalism against mosques are rising. Plans to build new ones sprout not-in-my-backyard protests and even calls to outlaw them. Muslim women complain that bans on head scarfs trample their religious rights. In Florida, congressional candidate Allen West, who has been endorsed by Sarah Palin, has said Islam is not a religion but "a totalitarian theocratic political ideology."
Blogs such as Stop Islamization of America and Creeping Sharia have helped lay the foundation for the controversy. And the culture war promises to grow even hotter. A fundamentalist Christian pastor who describes Islam as "of the devil" has called for an "International Burn a Quran Day" to mark the ninth anniversary of 9/11 next month. A more mainstream minister, Franklin Graham, was booted from a prayer service at the Pentagon, where Muslim prayer is welcome, after he called Islam "evil."
Yet is any of this new? While nearly one in five believe, incorrectly, that Barack Obama is a Muslim, this is not the first time a president has been suspected of lying about his religion. Anti-Semites and Nazi sympathizers spread false rumors in the 1930s that Franklin Delano Roosevelt, a mainline Episcopalian, was Jewish.
The latest debate reveals "the dark underbelly of the American psyche," said Boston University religion professor Stephen Prothero, author of "God Is Not One: The Eight Rival Religions That Run the World--and Why Their Differences Matter." "We keep imagining that we've outgrown our religious bigotry and we haven't. It keeps getting tested for each new religious group."
Everything old is new again
Scholars liken today's Muslim bashing to similar episodes in American history. In the 19th century, the nativist Know-Nothing Party wanted to prevent immigrants, especially Irish Catholics, from coming to America. Prejudice against Mormons forced them to flee west to Utah. Anti-Semitism spawned lynchings as, of course, did racism.
In 1924, Congress clamped down on immigration from eastern and southern Europe -- home to such "undesirables" as Italians and Jews -- as well as all of Asia. And after the attack on Pearl Harbor, more than 110,000 Japanese-Americans living on the West Coast were forced into internment camps for the duration of World War II.
Today's debate over the mosque "is very mild compared to some of these previous episodes," said John Green, a University of Akron political scientist who studies religion and politics. He notes that religion, ethnicity and race are often conflated to produce a conflict between new groups and old groups.
"Each of these episodes has its unique circumstances," he said, "but they appear to be most severe when the unpopular group is linked to national security and the definition of the nation. 9/11 is a good example and many of these episodes were associated with wars. Other were linked to other crises like state rights, civil rights, immigration and communism."
Louise Cainkar, a Marquette University sociologist, sees similarities to anti-German sentiment during World War I and against the Japanese in World War II but says neither were as "strong or pervasive" as the feelings about Muslims. The only thing that comes close, she said, was the anti-Catholic movement of the 19th century that lingered in a less-virulent form until 1960, when presidential candidate John F. Kennedy had to affirm publicly that he would take no orders from the pope.
Religion and politics have often mixed in America, with uneven results. After 9/11, President George W. Bush rejected the formula that Islam equaled terrorism and spoke out loudly in favor of religious tolerance. In the current debate, political rhetoric has ranged from far right to moderate middle to wishy-washy to impassioned.
But Prothero was struck by two reactions "by politicians who should know better" -- Senate Majority Leader Harry Reid and Republican presidential hopeful Mitt Romney. Both men oppose the proposed Islamic center in lower Manhattan and both are Mormons.
"It's unconscionable and frankly shocking that any Mormon would speak on this issue the way Romney and Reid have spoken. Don't they remember that the founder of their religion was assassinated by an anti-Mormon mob?" said Prothero, who also wrote "Religious Literacy: What Every American Needs to Know -- And Doesn't."
Yet he said the men are typical of Americans who live in one of the most religious countries on earth but are "astonishingly ignorant" about religion. He noted that Imam Faisal Abdul Rauf, who heads the Cordoba Initiative behind the proposed Islamic center, is a Sufi. Sufism is a tolerant strain of Islam that Osama bin Laden and al-Qaida consider an infidel religion and whose shrine in Pakistan was recently the target of a double suicide bombing.
"I find the lack of memory frightening," Prothero said. "This is a classic moment when it helps to remember something about American history – that our freedoms have been hard won."
Muslims in America
Akbar Ahmed, chairman of the Islamic studies department at American University and a former Pakistani diplomat, visited 100 mosques in 75 cities over the last year for his new book, "Journey Into America: The Challenge of Islam." What he found in interviews with Muslims and non-Muslims, native-born and immigrant, was a common feeling of being under siege from a faltering economy, natural disasters and two wars at a time when the first non-white president in history "has become a lightening rod for everything that is going on in America."
But he said the controversy "is not just about one mosque, although that is a very special and sensitive one because of 9/11. It is much more."
Ahmed said Muslims haven't had the chance to go through "the process of Americanization that successive waves of immigrants" did before them.
When the Immigration Act of 1965 opened the door for the first time to people from Third World countries -- many of them Muslims -- the doctors, lawyers and engineers who came "flew straight into the American dream," Ahmed said. "Nobody challenged them. They didn't go through the century-long process that Italians and Jews did" to be accepted. But when 9/11 happened, "People said, 'Who are these Muslims? We don't know anything about them' " and some quickly equated the 19 hijackers with all Muslims in America.
"Some Muslims have been here five generations," Ahmed said, "but today they are all under a cloud."
Cainkar, author of "Homeland Insecurity: The Arab American and Muslim American Experience after 9/11," noted that Arabs have lived in America for more than a century but anti-Arab feelings intensified only after the Six-Day War in 1967 and have since combined to inflame ill will toward Muslims. Today, she said, those speaking out against the proposed mosque are motivated by more than just religious beliefs.
"Some have foreign policy interests. Some think a strong America means controlling Muslim movements and countries. Some support Israel and so understand that to mean opposing Muslims. Some have a conservative view of American society and think it should be Euro-American. Some don't like people of color. Some believe Jesus is our savior and other religions are false. Some just like to hate," she said.
"It is not really about Muslims at all -- they actually know very little about them."