Simplify the following text for a Grade 8 native English-speaking person.
Original: Hurwicz and his family experienced persecution by both the Bolsheviks and Nazis , as he again became a refugee when Hitler invaded Poland in 1939 .
Simplified: Hurwicz and his family were treated very badly by the Bolsheviks and Nazis because they were Jewish . He became a refugee again when Hitler invaded Poland in 1939 .