In 1937, in what would prove to be a successful effort to control Germany culturally as well as politically, Hitler and his fellow Nazis confiscated what they labeled as degenerate art from German museums. Soon thereafter many of the creators of these condemned artworks were arrested.On Sept. 1, Trump and his cohort, without consultation with those with knowledge about art that isn’t gold, removed Joel Shapiro’s sculpture “Blue” from the grounds of the Kennedy Center of the Performing Arts. Google the charming sculpture, which Shapiro described as being “about action and risk and performance and energy. It’s a celebration of...