I went to a decent school and we never covered this. I’ve since learned that it happened, and the pivotal event it was, but for anyone else this quick Britannica summary shows its significance in not too many words:

Just before midnight on November 9, Gestapo chief Heinrich Müller sent a telegram to all police units informing them that “in shortest order, actions against Jews and especially their synagogues will take place in all of Germany. These are not to be interfered with.” Rather, the police were to arrest the victims. Fire companies stood by synagogues in flames with explicit instructions to let the buildings burn. They were to intervene only if a fire threatened adjacent “Aryan” properties.

In two days and nights, more than 1,000 synagogues were burned or otherwise damaged. Rioters ransacked and looted about 7,500 Jewish businesses, killed at least 91 Jews, and vandalized Jewish hospitals, homes, schools, and cemeteries. The attackers were often neighbours. Some 30,000 Jewish males aged 16 to 60 were arrested. To accommodate so many new prisoners, the concentration camps at Dachau, Buchenwald, and Sachsenhausen were expanded.

After the pogrom ended, it was given an oddly poetic name: Kristallnacht—meaning “crystal night” or “night of broken glass.” This name symbolized the final shattering of Jewish existence in Germany. After Kristallnacht, the Nazi regime made Jewish survival in Germany impossible.

Take this is conjunction with Sheriff what’s his face saying they need to document everyone with Kamala signs out front, and you can see some dots start to connect why people are feeling stressed.