In the case of Nixon v. Herndon, a black man named Lawrence A. Nixon was denied his right to vote in a Democratic primary election in Texas due to state laws prohibiting African Americans from participating. The Supreme Court ruled unanimously that this law violated the Fourteenth Amendment's Equal Protection Clause, which guarantees all citizens equal protection under the law regardless of race or color. This decision marked an important step towards racial equality and voting rights for African Americans, though it would take several more decades before these rights were fully realized nationwide.

The Nixon v. Herndon case did not have a dissenting opinion; the decision was unanimous. The U.S Supreme Court ruled that Texas's law barring African Americans from participating in Democratic primary elections violated the Fourteenth Amendment's Equal Protection Clause, thereby making it unconstitutional.