In 1936, New Yorkers approved a radical change in local democracy. By a margin of nearly two to one, they replaced the corrupt board of aldermen with a city council elected via proportional representation (PR). Rather than traditional winner-take-all elections between two candidates representing two political parties, PR allowed voters to rank candidates on their ballots in order of preference and guaranteed victory to anyone polling more than 75,000 votes. This system enabled the election of the most diverse legislatures in New York's history, comprised of the city's first African American...