Intelligence Brief: Political Polarization and Historical Precedent The United States experienced comparable levels of partisan division in the 1850s-1860s preceding the Civil War, with approval ratings for Congress dipping to 9% in 2013—lower than during Watergate (21% in 1974). Today's polarization reflects structural factors: gerrymandering has created 435 House districts where roughly 80% lean decisively toward one party, social media algorithms amplify ideological segregation, and straight-ticket voting has increased from 26% (1992) to 87% (2020). This matters because historical periods of extreme polarization preceded democratic breakdowns or major constitutional crises—understanding these patterns helps identify whether current divisions represent cyclical politics or systemic institutional failure requiring structural reform.