1960 was one of the few (and one of the last) elections where both candidates did "well" just about everywhere. Relatively speaking.
Yeah, it was also the last election where a Democrat won at least one county in every state.
1996 I believe
Yes, Bubba won at least one county in every state.
I thought it would have been 2000 but apparently Gore didn't win any counties in Utah or Wyoming (not helped by Nader but Bush did get over 50% in Summit and Teton Counties, which would be shocking today).
Interestingly there are 2 clinton romney counties and only 1 obama trump county in NE.
