I’m working on some charts and maps showing which counties have a consistent bias for or against the incumbent party in presidential elections, which may take a little while. As a sneak preview, here are the major counties with the biggest vote swings in the last three elections where the incumbent party lost. In 1980, Jimmy Carter’s slide in Worcester, Massachusetts, was exacerbated by the presence of John Anderson on the ballot; in 1992, the third-party candidacy of Texan Ross Perot accelerated the first President Bush’s drop in the Lone Star state; and in 2000, the second George Bush did particularly well in Texas. Overall, though, anti-incumbent (angry? bitter?) counties seem most common in Florida, Texas, and the West. Are they a good predictor as to how well the Democrats will do this fall?

Biggest swings against incumbent party among counties casting at least 100,000 votes

1980: Clark (Las Vegas), Nevada. Drop of 19 points for Jimmy Carter (from 50% to 31%).
Worcester, Massachusetts. Drop of 18 points (from 60% to 42%).
Miami-Dade, Florida. Drop of 18 points (from 58% to 40%).

Biggest swings against incumbent party among counties casting at least 100,000 votes

1992: Collin (suburban Dallas), Texas. Drop of 27 points for George H.W. Bush (from 74% to 47%).
Brevard (Melbourne), Florida. Drop of 27 points (from 70% to 43%).
Denton (suburban Dallas), Texas. Drop of 26 points (from 68% to 42%).

Biggest swings against incumbent party among counties casting at least 100,000 votes

2000: Travis (Austin), Texas. Drop of 11 points from Bill Clinton to Al Gore (from 52% to 42%).
Salt Lake, Utah. Drop of 7 points (from 42% to 35%).
Hidalgo (Mexican border), Texas. Drop of 6 points (from 67% to 61%).