How did most americans react to mao zedong's victory in china?

The correct answer is Most Americans were stunned and blamed the Truman administration.

They were all suffering from the politics which blamed communism for everything and they lived in fear out of it. Since China, a huge country became fully communist under Mao, they were afraid of it and believed that Truman was responsible for it because he did nothing to prevent it like he did for some other countries.