Is Islam a religion of peace, as President George W. Bush said at the Islamic Cultural Center of Washington six days after 9/11? Or is it, as evangelist Franklin Graham has argued, a "very evil and wicked religion"?
Is the United States a mult-religious nation of "Christians and Muslims, Jews and Hindus and nonbelievers," as Obama said in his first inaugural address? Or is it a Christian nation that should temporarily bar all Muslims from entering the country, as GOP presidential frontrunner Donald Trump has proposed?
Finally, is Obama, as roughly half of Republicans now believe, a Muslim masquerading as a Christian?
For a while after 9/11, it seemed as if the nation's informal religious establishment, which had previously morphed from Protestant to Christian to Judeo-Christian was poised to become "Abrahamic," embracing Judaism, Christianity and Islam as three branches of a common faith.
But the love-bombing eventually gave way to fear. And terrorist attacks at Paris and San Bernardino seemed proof to many of Ben Carson's claim that Islam is "inconsistent with the values and principles of America."
Today many conservatives see tolerance as a Trojan Horse smuggling jihadis into the heartland. Some even claim that Islam is not entitled to First Amendment protections because, as televangelist Pat Robertson has argued, "Islam is not a religion. It is a worldwide political movement meant on domination."
America's Islam wars go back much farther than 9/11, however.
During debates over the Constitution, proponents of a religious test for federal office said that the absence of such a test would make it "most certain that Papists may occupy [the presidency], and Mahometans may take it."
During the rough-and-tumble election of 1800, Thomas Jefferson was accused of being a secret Muslim. "No one knows," wrote the Connecticut Courant, "whether Mr. Jefferson believes in the heathen mythology or in the alcoran (Quran)."
In our 19th-century anti-Mormon culture war, the specter of Islam loomed again. In this, the broadest assault on any religion in U.S. history, the governor of Missouri issued an order to exterminate the Mormons and the U.S. Army was dispatched to quell them. Presidents denounced them in State of the Union addresses.
Both houses of Congress refused to seat duly elected Mormon representatives. Mobs killed their founder and terrorized his followers, chasing them from upstate New York to Utah. In one particularly egregious case, the good citizens of Fleming County, Kentucky, tore down a Mormon church stud by stud in order to prevent members from collecting fire insurance.
Critics also tarred and feathered Mormonism with unflattering comparisons to Islam. Like Muhammad, founder Joseph Smith (the "Yankee Muhammad") and his successor Brigham Young ("the Muhammad of Salt Lake") were said to be false prophets peddling a false Bible and hell-bent on advancing their false religion by force.
As anti-Mormon activist Jennie Fowler Willing wrote, both Mormonism and Islam "proselyte by violence" and "aim at universal domination." So Mormonism wasn't really a religion, it was "a great financial and political scheme."
We flatter ourselves with our schoolbookish vision of the United States as a nation of immigrants and a nation of religions, forever crafting a peaceful "unum" out of this discordant "pluribus." But repeatedly we have failed to live up to our ideals, attacking and even killing our fellow citizens because "they" did not worship or look like "us."
After 9/11, President Bush rightly resisted the temptation to heed the fallen angels of our nature. President Obama, too, has refused to turn the war on terrorism into a crusade on the world's 1.6 billion Muslims. In a counterpoint to the martial drumbeat of the right, Obama has been ringing the bell of religious liberty. "When politicians insult Muslims," he said at his State of the Union address in January, "it betrays who we are as a country."
It is impossible to predict how our Islam wars will turn out, but I believe that eventually our Muslim population will grow large enough and the American principle of liberty will resound loudly enough and Muslims will be included in the American family.
Why? Because we have run this gauntlet before.
In 1800, Thomas Jefferson became president despite fears that his "infidel" administration would seize our Bibles. In 1960, the "papist" John Kennedy won the White House. In 2012, no one in possession of their sanity denounced Mitt Romney for his Mormon faith.
None of this has been accomplished without struggle, or course. So I am grateful to our President for traveling to Baltimore on Wednesday to fight the good fight, not only for our Muslim neighbors, co-workers, sisters and husbands, but also for what the great social reformer Frederick Douglass once hopefully described as "our composite nation."