Heflin argued, successfully, for completely excluding Black Alabamians from voting, stating, "God Almighty intended the negro to be the servant of the white man."

As Secretary of State in 1903, Heflin was an outspoken supporter of men put on trial for enslaving black laborers through fraudulent convict leasing.

He argued before a group of Confederate veterans that forcing blacks to labor was a means to hold them in their proper social position.

Heflin’s 1914 resolution made no mention of carnations, but requested that the U.S. flag be displayed at government offices, homes, and businesses across the country, “as a public expression of our love and reverence for the mothers of our country.” After quickly passing the House and being directed through the Senate by former Representative Morris Sheppard of Texas, the bill went to the President’s desk on May 8, and became law that same day.

[4] 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.

Returning to Washington to serve out his term, Heflin initiated a Senate investigation of voting fraud to try to overturn Bankhead's election.

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.

In 1937, the Imperial Wizard, Hiram Wesley Evans, told the press that Heflin had joined the secret order in the late 1920s.