ELECTORAL POLARIZATION: THE STRUCTURAL SHIFT U.S. partisan sorting has reached historic extremes—in 1994, 64% of Republicans were more conservative than the median Democrat; by 2017, that figure climbed to 97%. Simultaneously, geographic clustering intensified: in 1976, only 26% of Americans lived in landslide counties (winning margins >20%); by 2020, that surged to 60%, meaning most voters live among ideological near-clones. This structural realignment means swing voters have nearly vanished (down from ~25% of the electorate in the 1980s to ~5% today), fundamentally changing how campaigns operate and legislation passes. The outcome: Congress faces cascading gridlock, elections function as binary tribal contests rather than persuasion events, and compromise has become politically toxic in both parties—reshaping governance feasibility itself.