it's from Blackshirts and Reds:

During the cold war, the anticommunist ideological framework could
transform any data about existing communist societies into hostile
evidence. If the Soviets refused to negotiate a point, they were intransigent and belligerent;
if they appeared willing to make concessions,
this was but a skillful ploy to put us off our guard. By opposing arms
limitations, they would have demonstrated their aggressive intent; but
when in fact they supported most armament treaties, it was because
they were mendacious and manipulative. If the churches in the USSR
were empty, this demonstrated that religion was suppressed; but if the
churches were full, this meant the people were rejecting the regimes
atheistic ideology. If the workers went on strike (as happened on
infrequent occasions), this was evidence of their alienation from the
collectivist system; if they didn t go on strike, this was because they
were intimidated and lacked freedom. A scarcity of consumer goods
demonstrated the failure of the economic system; an improvement in
consumer supplies meant only that the leaders were attempting to
placate a restive population and so maintain a firmer hold over them.

If communists in the United States played an important role
struggling for the rights of workers, the poor, African-Americans,
women, and others, this was only their guileful way of gathering support
among disfranchised groups and gaining power for themselves.
How one gained power by fighting for the rights of powerless groups
was never explained. What we are dealing with is a nonfalsifiable
orthodoxy, so assiduously marketed by the ruling interests that it
affected people across the entire political spectrum.