If we exclude elections dominated by third party candidates – where one often does best by combining with one of the other major party – then these large trends all fall into three groups:
- swings against Bryan in the West due to evaporation of the free silver issue before the 1900 election
- swings against Hoover in Outer South due to the Great Depression and elimination of the anti-Catholicism that helped him carry TX, FL, NC, VA, TN and OK in 1928, and nearly carry AL
- swings to Carter in 1976 as a southern favorite son after the South overwhelmingly rejected McGovern (in the Deep South, Nixon actually won more of the black vote than McGovern did of the white vote)
Good summary. For UT in 1900, I think it's also at least partially because of successful Republican efforts to court Mormon leaders. For 1932, I'd also note that it's probably the only time in American history where an indisputable landslide for one party was immediately followed by an indisputable landslide for the opposite party.
I'd add that for ND in 1920, it's at least partially because of an absolutely massive shift towards Republicans, particularly outside of the South. 1920 is kind of a fascinating election for the degree in which it represented a repudiation of the Democratic Party, and Harding retains the record for the largest popular vote margin. ND had the most striking shift, going from 48D-46R to 78R-18D, but there were plenty of other states that had massive swings (e.g. MN went from a 0.1% Democratic victory to a 50-point Republican victory).
I'm assuming you mean a 0.1%
Republican victory. The state never voted Democratic at the presidential level prior to 1932.
