It's Islam now; it was Bolshevism then. It's Middle Easterners now; it was southern and eastern Europeans in the 1920s. My father came here in Aug 1920. Had he, and my Aunt Martha, tried to come a few years later, they might not have gotten in. In 1924, Congress, responding to nativist hysteria, created restrictions for immigrants from certain countries, including Greece. For instance, the quota, for Greece, in 1925 was 100. What are the odds that the teenaged brother and sister, Demetrios and Martha Skarlatos, would both have gotten in? They would have been 2% of the entire quota for the country for the entire year. There were at least 23 Greek immigrants coming in to Ellis Island, on the S.S. Themistokles, that day (I have a copy of the ship's manifest, in my lap, as I type this). One ship, on one day.
But my father got in. He was a resident alien for 16 years, before being granted citizenship. Depending on what time it is, and who is interpreting the rules, green card holders from restricted countries may not be able to return to the U.S. under Trump's Muslim ban. If those rules had applied in the 1920s and 1930s, people like my father could not have visited their relatives in Greece, and returned to the United States. Now, as it happens, my father never returned to Greece. But, his brother John did. He returned after the Spanish Flu pandemic to collect two of his orphaned siblings and bring them to America. My Uncle John was a resident alien, had a business and a wife in the U.S. What if a ban, such as the one now imposed on Muslims from certain countries, was imposed in 1920? He would have left the U.S. to settle his family's affairs and care for his siblings, only to find himself unable to return to his wife and business in the U.S. The United States of America: the country he had fought for in the trenches of France, in World War I.
There is a reason some of us are reacting so viscerally to Trump's actions. A short dictionary definition of 'empathy' is "the ability to understand and share the feelings of another".