Heflin continued to serve in the House until 1920, when he was elected to the
Senate to fill the vacancy caused by the death of
John H. Bankhead. In the 1920s, he expressed strong hostility to the
Knights of Columbus. In 1928, Heflin further expressed outrage that
Al Smith was
the party's nominee and inveighed against Catholic influences on the Democratic Party; he attacked Smith and the
pope on the Senate floor, and "embarked on a nationwide speaking tour, partially funded by the KKK." Instead of Smith, he supported
Republican Herbert Hoover for President and is sometimes credited with coining the term "
yellow dog". The Democrats thus did not renominate Heflin for the Senate in 1930. He ran as an independent candidate, losing decisively to
John H. Bankhead II. Returning to Washington to serve out his term, Heflin initiated a Senate investigation of voting fraud to try to overturn Bankhead's election. The inquiry lasted 15 months and cost $100,000. In the same year, Heflin officially protested in the Senate against
New York's legalization of racial
intermarriage between a black man and a white woman. New York Senator
Royal S. Copeland reacted angrily to Heflin, who replied that if Copeland went someday to the
South on a presidential campaign, he would be
lynched and
hanged by the population. In April 1932, with Heflin's term expired and Bankhead seated, the Senate prepared to vote on a committee recommendation against Heflin. He delivered a five-hour oration, punctuating his remarks with vehement gestures and
racist jokes. As he thundered to a conclusion, the gallery audience, packed with his supporters, jumped to its feet with a roar of approval. They were ordered out of the chamber. Two days later, the Senate voted by a wide margin to dismiss Heflin's claim. Heflin was suspected of being a member of the
Ku Klux Klan. In 1937, the
Imperial Wizard,
Hiram Wesley Evans, told the press that Heflin had joined the secret order in the late 1920s. ==Later life==