As the former House Speaker, Bouanchaud was chosen president of the Louisiana Constitutional Convention in 1921. The document produced by that convention remained in force until 1975 during the administration of GovernorEdwin Edwards.
In 1924, Lieutenant Governor Bouanchaud ran for governor against Henry L. Fuqua, and Huey Pierce Long, Jr. Bouanchaud and Fuqua received the most votes in the first Democratic primary held on January 15, 1924, with Long of Winnfield, having been eliminated from contention that year. Long then gained the governorship four years later in 1928. Fuqua defeated Bouanchaud in the second Democratic primary held on February 19, 1924.