Sessions’s characterization falls into a nether region between truth and falsehood. Perhaps his is the best comment to begin with precisely because it is a half-truth. Yes, after 1941, concentration camps held Jews to prevent them from leaving Germany — but also to consolidate them for extermination. However, for more than eight years earlier, the camps generally were used for the opposite purpose: to force Jews to emigrate from Germany by making life intolerable, in part by separating men from their families. This is precisely the kind of important historical nuance lost in the hysteria surrounding Trump’s callous immigration policy. There are valuable comparisons to be made, but they must be historically informed.
Racism and antisemitism were basic tenets of the NSDAP and the Nazi regime. Nazi Germany's racial policy was based on their belief in the existence of a superior master race. The Nazis postulated the existence of a racial conflict between the Aryan master race and inferior races, particularly Jews, who were viewed as a mixed race that had infiltrated society and were responsible for the exploitation and repression of the Aryan race.
The first concentration camps in Germany were established soon after Hitler's appointment as chancellor in January 1933. In the weeks after the Nazis came to power, The SA (Sturmabteilungen; commonly known as Storm Troopers), the SS (Schutzstaffel; Protection Squadrons—the elite guard of the Nazi party), the police, and local civilian authorities organized numerous detention camps to incarcerate real and perceived political opponents of Nazi policy.