Some more longtime Democratic counties that might flip if Trump improves upon 2016:
- Deer Lodge, MT (D since 1928)
- Carlton, MN (D since 1932)
- Lake, MN (D since 1936)
- Portage, WI (D since 1960)
- Clatsop, OR (D since 1960)
- St. Clair, IL (D since 1976)
- Iberville Parish, LA (D since 1976)
- Grant, NM (D since 1984)
- Cibola, NM (D since 1988)
- Franklin, VT (D since 1988)
- Merrimack, NH (D since 1992)
- Clinton, NY (D since 1996)
Last I checked, all the McCain -> Obama counties flipped back to Trump.
Was this because of voter ID laws cutting into black turnout? Still, that hardly explains Chaffee County.