"how did the soviet focus on social and economic rights in the cold war human rights debate affect american attitudes"

Basically, people were scared of communism, that was the general sentiment. Anything progressive that was used in communist countries or was implemented was deemed by the American masses as the first step towards socialism and it was easy to discard any disliked policies in this way, just associate them to communists and it would never get passed.

The answer is crop yield.