Flanders was noted for introducing a 1954 motion in the Senate to censure Senator Joseph McCarthy. McCarthy had made sensational claims that there were large numbers of Communists and Soviet spies and sympathizers inside the federal government and elsewhere. He used his Senate committee as a nationally televised forum for attacks on individuals whom he accused. Flanders felt that McCarthy's attacks distracted the nation from a much greater threat of Communist successes elsewhere in the world and that they had the effect of creating division and confusion within the United States, to the advantage of its enemies. Ultimately, McCarthy's tactics and his inability to substantiate his claims led to his being discredited and censured by the United States Senate.