In the case of Branigin et al. v. Duddleston et al., 1967, the U.S Supreme Court examined Indiana's legislative apportionment scheme which allowed each county to have at least one representative in the state legislature regardless of population size. The plaintiffs argued that this violated their Fourteenth Amendment rights by diluting their votes compared to those living in less populated counties (the principle of "one person, one vote"). However, the court upheld Indiana's system with a 6-3 decision. They reasoned that while it did result in some disparities between districts' populations and representation levels, these were not severe enough to be unconstitutional as they fell within an acceptable range under previous rulings on apportionment cases.

In the dissenting opinion for Branigin et al. v. Duddleston et al., Justice Douglas argued that Indiana's apportionment plan violated the Equal Protection Clause of the Fourteenth Amendment, which requires states to ensure equal representation for all citizens in both houses of their legislatures. He believed that population should be the only standard used when determining legislative districts and any deviation from this principle would undermine democracy by giving some voters more influence than others based on where they live. The majority upheld Indiana's use of a "quota" system, allowing each county at least one representative regardless of its population size, but Douglas contended this method was inherently unequal and unconstitutional because it resulted in significant disparities between districts' populations - thus violating principles established in previous cases such as Reynolds v. Sims (1964). In his view, every citizen should have an equally effective voice in electing representatives; anything less would compromise fundamental democratic ideals.