President Trump’s executive order to sharply restrict immigration from seven predominantly Muslim countries has been decried by many as reckless, punitive, and even unconstitutional. Nearly half the electorate, however, applaud the president for suspending immigration even if it means turning back refugees, many of whom are innocent victims of the political violence besetting the Middle East. American presidents have periodically curtailed the entry of individuals or groups in the name of national security. Such measures invariably have proven controversial, often unleashing a fiery public debate about the relative merits of protecting the homeland at the cost of undermining our values. 
One such moment that may be instructive for the present occurred during the spring of 1940, when a succession of lightning-quick German victories throughout Western Europe led Franklin Roosevelt to raise the specter of Nazi infiltration into the Americas in one of his fireside chats.  The Roosevelt administration’s subsequent decision not to provide visas to any refugees then living in German-occupied territory and Washington’s insistence on vetting exiles headed to the Caribbean would have significant implications for a small group of Central European Jewish exiles attempting to flee Nazism.  Invited by the ruthless Dominican dictator, General Rafael Trujillo, to become farmers in the tropics, these stateless exiles now found their futures in jeopardy, thanks to Washington’s restrictive immigration policies.  Yet they knew they were the fortunate ones; many more remained trapped and unable to get out of Europe.