Why did senator joe McCarthy claim while giving a speech in wheeling West Virgina?

In his speech in Wheeling, West Virginia, on February 9, 1950, Senator Joe McCarthy claimed to have a list of communists who were working in the U.S. State Department. He argued that these individuals posed a significant threat to national security and were undermining American values. This speech marked the beginning of McCarthy's campaign against alleged communist infiltration in the government, leading to the infamous period of McCarthyism. His assertions were controversial and sparked widespread fear and paranoia during the Cold War era.