Answer
BY charging that Communists had infiltrated the government
Explanation
Joseph McCarthy was a republican US senator from Wisconsin and he was one of the most controversial figures in American politics. He widely scattered charges that gave rise to a new world of McCarthyism . McCarthyism is the practice of making accusations of subversion or treason without proper regard for evidence.Many different people in the United State in those days had different views about Joseph McCarthy, some of them praised him while others condemned him for publicly accusing people of disloyalty without evidence.