What the county data actually shows, once you separate a place's own movement from what the country was doing that year.
Arizona's decisive county has a raw margin that lurches from R+14.6 to D+2.2 and back — but measured against the nation, it has moved one direction for four straight cycles, from R+18.1 to R+2.0.
Politigoat Data Desk
For four straight cycles Macomb voted within two points of the national margin; in 2016 it moved 14.3 points in a single election and has sat there ever since.
Politigoat Data Desk
Four of the largest partisan shifts among sizable counties sit in one metro area, and seven counties there posted the maximum six consecutive cycles of same-direction movement.
Politigoat Data Desk
Counties that "always pick the winner" are graded on a one-bit test. Grade them on distance from the national margin instead, and among counties of real size, Montgomery County, Ohio and Bucks County, Pennsylvania come out on top.
Politigoat Data Desk
353 counties have changed sides at least twice since 2000, and the ones that flip most often turn out to be the steadiest places on the map.
Politigoat Data Desk
Elasticity is the slope of a county's margin against the country's — above 1 amplifies, near zero ignores, and below zero means something considerably stranger than it sounds.
Politigoat Data Desk