On July 27, 1940, African American Lonnie Smith went to cast his ballot in the Texas Democratic Party primary election, but as in his previous attempts, he was refused. Since Reconstruction, some states had denied black participation in Democratic Party primaries. Since Democratic candidates were overwhelmingly victorious in the South, voting in those primaries was critical to choosing one’s electors.

Lonnie Smith challenged the constitutionality of all-white primaries in the U.S. Supreme Court. In 1944, the Smith v. Allwright decision overturned years of precedent by declaring all-white primaries unconstitutional. Thurgood Marshall, who represented the NAACP in the case, considered it his most important victory.