How Politically Diverse Are U.S. Police Agencies?

This study asks whether partisan differences among U.S. local police officers translate into different enforcement behavior. The authors merge personnel rosters from 99 of the 100 largest local U.S. agencies with voter files to measure police partisanship and then use detailed operational data from Chicago and Houston to compare actions of Democratic and Republican officers facing comparable situations. They report that police are generally more Republican than their jurisdictions, but that after correcting for multiple comparisons there are minimal detectable differences in on‑the‑ground enforcement by partisan affiliation. The authors do, however, document consistent racial differences: in Chicago, Black and Hispanic officers make fewer stops and arrests, and in both Chicago and Houston Black officers use force less often; additionally, in Chicago White Democrats make more violent‑crime arrests than White Republicans. The abstract frames these findings cautiously and emphasizes limits to detectable partisan effects despite partisan composition differences.