Two-party vote share is used for all elections except 1948, when the Dewey vote share is used, and 1968, when the Humphrey vote share is used in the first chart. In the second, the Dem vote share is used for 1832 (excluding uncontested states), 1856, 1860, 1912, 1964, and 1968, the GOP share is used for 1892 (excluding FL) and 1948.

This was the most polarized U.S. election since 1932, when the battle was between a protectionist, pro-business Republican northeast and everyone else (Ohio almost went for Hoover due to GOP strength in Eastern Ohio). With exceptions (GA, ME, TX, RI), red states (ND, SD, WV, AL) are becoming redder; blue states (MA, CA, WA, MD) bluer.