There are usually fewer state senators than there are members in a state's lower house. In the past, this meant that senators represented different regions within a state, not according to the population of the region. This was a way of balancing the power of the lower house, where the numbers for each state were related to the state's population. In 1963, the Supreme Court of the United States ruled that state legislatures must give seats in both houses depending on the population of the state.
- See Gray v. Sanders, 372 U.S. 368 (1963)