structural:expansion
Voting patterns

Morris P. Fiorina (2006, 2008) posits the hypothesis that polarization is a phenomenon which does not hold for the public, and instead is formulated by commentators to draw further division in government. Others, such as social psychologist Jonathan Haidt and journalists Bill Bishop and Harry Enten, instead note the growing percentage of the U.S. electorate living in " landslide counties ", counties where the popular vote margin between the Democratic and Republican candidate is 20 percentage points or greater. In 1976, only 27 percent of U.S. voters lived in landslide counties, which increased to 39 percent by 1992. Nearly half of U.S. voters resided in counties that voted for George W. Bush or John Kerry by 20 percentage points or more in 2004. In 2008, 48 percent of U.S. voters lived in such counties, which increased to 50 percent in 2012 and increased further to 61 percent in 2016. In 2020, 58 percent of U.S. voters lived in landslide counties. At the same time, the 2020 U.S. presidential election marked the ninth consecutive presidential election where the victorious major party nominee did not win a popular vote majority by a double-digit margin over the losing major party nominee(s), continuing the longest sequence of such presidential elections in U.S. history that began in 1988 and in 2016 eclipsed the previous longest sequences from 1836 through 1860 and from 1876 through 1900. Other studies indicate that cultural differences focusing on ideological movements and geographical polarization within the United States constituency is correlated with rises in overall political polarization between 1972 and 2004.