discriminatory. The Court ruled in the related case Myers v. Anderson (1915), that the officials who enforced such a clause were liable for civil damages. The Court addressed the white primary system in a series of decisions later known as the "Texas primary cases". In Nixon v. Herndon (1927), Dr. Lawrence A. Nixon sued for damages under federal civil rights laws after being denied a ballot in a Democratic party primary election on the basis of race. The Court found in his favor on the basis of the Fourteenth Amendment, which guarantees equal protection under the law, while not discussing his Fifteenth Amendment claim. After Texas amended its statute to allow the political party's state executive committee to set voting qualifications, Nixon sued again; in Nixon v. Condon (1932), the Court again found in his favor on the basis of the Fourteenth Amendment. Following Nixon, the Democratic Party's state convention instituted a rule that only whites could vote in its primary elections; the Court unanimously upheld this rule as constitutional in Grovey v. Townsend (1935), distinguishing the discrimination by a private organization from that of the state in the previous primary cases. However, in United States v. Classic (1941), the Court ruled that primary elections were an essential part of the electoral process, undermining the reasoning in Grovey. Based on Classic, the Court in Smith v. Allwright (1944), overruled Grovey, ruling that denying non-white voters a ballot in primary elections was a violation of the Fifteenth Amendment. In the last of the Texas primary cases, Terry v. Adams (1953), the Court ruled that black plaintiffs were entitled to damages from a group that organized whites-only pre-primary elections with the assistance of Democratic party officials. The Court also used the amendment to strike down a gerrymander in Gomillion v. Lightfoot (1960). The decision found that the redrawing of city limits by Tuskegee, Alabama officials to exclude the mostly black area around the Tuskegee Institute discriminated on the basis of race. The Court later relied on this decision in Rice v. Cayetano (2000), which struck down ancestry-based voting in elections for the Office of Hawaiian Affairs; the ruling held that the elections violated the Fifteenth Amendment by using "ancestry as a racial definition and for a racial purpose". After judicial enforcement of the Fifteenth Amendment ended grandfather clauses, white primaries, and other discriminatory tactics, Southern black voter registration gradually increased, rising from