25 years ago, my wife and I visited Germany. One Sunday, rather than attending a church service we would not understand, we toured Dachau. It was eerie, because it is surrounded by a tree-lined green belt that is beautiful. The mental contrast between that beauty and the evil done there was horrifying. The former camp area is now empty, except for a couple of restoration barracks (tracing the camp's stages from WW1 factory worker camp through post WW2 refugee camp). The original administration building is a museum with exhibits about the concentration camp system, torture, etc.. Painting with a broad brush, there were lots of work camps all over Germany (where many died), Dachau, which was for political opponents (there may have been similar political-prisoner camps; again many died there), and extermination camps like Auschwitz.
There is nothing in the US even slightly like any sort of Nazi concentration camp - not even FDR's internment camps. Any DU-member who has visited Dachau or Auschwitz or some other concentration camp knows this. Any DU-member who has visited an actual Nazi concentration camp and still claims Trump is doing the same is knowingly and grossly lying.