The fault, dear Brutus, is not in the stars / But in ourselves. – Shakespeare, Julius Caesar, Act I, Scene III

The mass shooting of Jewish congregants at the Tree of Life synagogue in Pittsburgh this past weekend is part of a rise in anti-Semitic attacks and underscores the continuing challenge of addressing the issue of religious tolerance in America. The shooter was incensed at Jews because, as he wrote on social media, HIAS (founded as the Hebrew Immigrant Aid Society) was working with local synagogues to assist in resettling refugees around the country. He posted: “You like to bring in hostile invaders to dwell among us? We appreciate the list of friends you have provided.” Included was a link to a congregation that used the Tree of Life building.

Such tragic events often coincide with periods of intolerance within society at large. Throughout our history, moral panics about the dangers posed by people from disparate religious, ethnic, and political backgrounds have often been used to create “Others” who are singled out as scapegoats for a multitude of social problems. Religious minorities like Jews, Catholics, and Muslims have, at various times in our nation’s history, made easy targets.   

From 1830 to 1860, a fear of Catholics fostered widespread division. A feature of the social landscape since colonial times, anti-Catholic sentiment rose dramatically in the 1830s with the rise of nativism, which held that established or native-born citizens were superior to new or recent arrivals. Nativists opposed all immigration, but especially that ofCatholics, who were rumored to owe their allegiance to the Pope. Followers were widely believed to be part of a conspiracy to bring down the government and install a Catholic leader.

During this period, anti-Catholic propaganda was rife in the popular press as Catholics were said to have infiltrated the highest rungs of government. This parallels present-day fears over the existence of a Deep State made up of Democratic Party sympathizers undermining the Trump administration. During the 1950s, the Deep State was believed to be composed of hundreds of godless communist subversives whom Wisconsin Senator Joseph McCarthy claimed were working as government bureaucrats. These fears triggered a secondary panic—the Lavender Scare: the fear that closeted gay and lesbian employees of the federal government would compromise national security by being susceptible to blackmail by communist agents. At least 5,000 government workers were purged from the civil service as a result. Their crime: the suspicion of being gay.

During the Catholic scare politicians and ultra-conservatives stoked fears that resulted in riots in several cities. In 1844, the streets of Philadelphia ran red with blood as thirteen people died and Catholic homes and churches burned to the ground. Catholics were the subject of vile rumors, harassment, discrimination, protests, and vigilante attacks.

The most incredible claims centered on convents and accounts of priests taking out their sexual fantasies and perversions on nuns. Stories of nuns serving as sex slaves captivated the public imagination and were a common theme in the literature that sprang up at this time. Rumors spread that many nuns had been brainwashed. Convents were said to contain dungeons where acts of torture took place and the newborns of forbidden liaisons were sacrificed in macabre rituals, their bodies disposed of in vats of acid.

In 1938, the U.S. government closed its doors to the throngs of German Jews who were desperate to seek sanctuary from their Nazi nightmare. For many, it was tantamount to a death sentence. Propaganda minister Joseph Goebbels was fond of pointing out that while his government was more than willing to let them go, few countries would take them. At the time, the Nazis were purging the Reich of Jews by transporting them to nearby countries. While President Franklin Roosevelt had harsh words for Hitler’s treatment of Germany’s Jewish population, his words alone were little comfort to those who were fighting for their very survival, and that of their families. The United States even put pressure on European countries not to take them in, because they supposedly posed an imminent threat to their national security.

This tragic episode took place amidst charges that many Jewish asylum-seekers were working for the Nazis and intent on infiltrating the country. Driven by anti-Semitism, bigotry, and a fear of spies, State Department officials deliberately created piles of bureaucratic red tape to slow the flow of refugees to a trickle. During the entire period that America was at war with Germany, only 21,000 Jewish refugees were allowed into the country: a mere 10 percent of the overall quota. Put another way, about 200,000 men, women, and children were turned away in their hour of need, without any compelling factual reason—only fear and prejudice.

The Catholic scare and the Jewish refugee panic parallel exaggerated fears over Muslim refugees and asylum-seekers who are fleeing war and persecution, and the Trump administration’s attempt to prevent them from entering the country on security grounds. While the threat is real, most U.S. terrorists are homegrown. According to a recent study of terrorism in the United States spanning four decades—a time during which 3.2 million refugees entered the country—no terrorist deaths were caused by a Muslim refugee.

The odds of an undocumented immigrant killing someone in a terrorist attack are over 10 billion to one. Attempts to halt the intake of refugees and immigrants from several Muslim majority countries because they pose a security risk are based on fear. It’s an exercise in chasing ghosts. The Trump administration’s attempts to use a religious test to determine who can or cannot enter the country set a dangerous precedent. According to Alex Nowrasteh of the libertarian Cato Institute, the odds of being murdered by a refugee in a terrorist attack in the United States are an astronomical three-and-a-half billion to one. This Islamic scare is driven by fear, not facts.

These examples of religious intolerance are testaments to the human propensity to create, believe, and spread salacious stories driven by longstanding stereotypes, rumors, and fear. When we give into our xenophobic fears, we risk redefining a religion as a cult, and devoutness as fanaticism, while sacred traditions may be viewed as irrational superstitions. When any one group is under threat for their religious freedoms, it’s a threat to all of us.

Moral panics are as much a part of the human condition as is the process of “Othering.” Perhaps the best strategy to foster tolerance in the current toxic political climate is to educate people on one simple and indisputable scientific reality: that despite one’s political, religious, or ethnic orientation, human DNA is 99 percent identical. Humans are a single species.