Missouri voters pass groundbreaking redistricting reform that actually promotes partisan fairness

In a major victory in the fight to not just end gerrymandering but actually ensure redistricting treats both parties fairly, Missouri voters have approved the "Clean Missouri" Amendment 1. This new constitutional provision overhauls the state's legislative redistricting process while also instituting broader ethics reforms (congressional redistricting would be unaffected). Currently, a bipartisan commission of political appointees draws the maps, which leaves open the risk that elected officials will make deals to protect incumbents of both parties, stifling competitive races.

By contrast, the new reform will have the state auditor draw up a pool of applicants from which a nonpartisan demographer would be selected. That person would then be tasked with drawing new legislative maps, subject to the commission's approval. The demographer would be explicitly directed to use a statistical model known as the "efficiency gap" that's designed to gauge partisan fairness, which we have previously explained in detail.

While the maps would not be designed to yield outcomes perfectly proportional to the popular vote, they would aim to treat both parties equally so that the party winning the most votes statewide also wins the most seats. Even though the current maps were drawn by a bipartisan commission, and even though Republicans consistently win more votes across the state than Democrats, these maps still give Republicans a significant advantage beyond what they’d be expected to receive. This reform will therefore promote greater partisan fairness and more competitive elections.