Kammala jumla mai zuwa: A cikin 1937, an kori Trotskyists daga Jam'iyyar Socialist, wani aiki wanda ya haifar da kafa Jam'iyyar Socialist Workers (SWP) a ƙarshen shekara. A cikin SWP, Burnham ya haɗu da Max Shachtman a cikin gwagwarmayar ƙungiya game da matsayin ƙungiyar SWP mafi rinjaye, wanda James P. Cannon ya jagoranta kuma Leon Trotsky ya goyi bayansa, yana kare Tarayyar Soviet a matsayin jihar ma'aikata da ta lalace a kan mamayar mulkin mallaka. Shachtman da Burnham, musamman bayan sun shaida yarjejeniyar Nazi-Soviet na 1939 da mamaye Poland, Latvia, Lithuania, da Estonia ta hanyar mulkin Joseph Stalin, da kuma
Soviet mamaye Finland a watan Nuwamba 1939, ya zo ya yi jayayya cewa USSR wani sabon nau'i ne na zamantakewar ajiyar mulkin mallaka kuma saboda haka bai cancanci ko da goyon baya mai mahimmanci daga ƙungiyar gurguzu ba.