Academia did indeed have quite a few Soviet sympathetic figure. Tbh, I'm not sure why the gp picked the 70's. The cold war was mostly thawing then as the failure of the USSR was becoming visible (though Reagan partly reignited it in 80s). The 1950s was a period where real and suspected sympathizers of the USSR were drummed out of their positions in academia, entertainment and elsewhere. The witch hunts died down in the 1960s as US society relaxed a bit itself.