(1909-57) a US politician in the REPUBLICAN PARTY . He became famous in the early 1950s by saying publically that many famous people, important politicians, and military officers were COMMUNIST s, and therefore enemies of the US. He influenced the development of strongly anti-Communist ideas in the US, and anyone who was called a Communist was treated extremely unfairly. In 1954, however, the US SENATE formally criticized his actions, and he lost most of his political support and power