The Los Angeles County Museum of Art last year held an exhibit of works by German artists from the interwar period. Among them was the modernist painter Ernst Ludwig Kirchner, who drew inspiration from the cultural artifacts that came to Germany during its short-lived colonial era in Africa and the Pacific, which was terminated by the Allied powers after World War I. Reflecting a core tenet of critical race theory, the curators scolded Kirchner for his “colonial” interests. He “encountered looted art in ethnographic museums that presented such work out of their cultural contexts,” an exhibit catalog complained . Curators...