Why did George Wallace do so poorly in Maine?

[Blow by blow, the passion dies]

Arostook was his worst county nationwide

[VPH]

1. New England was Wallace's weakest region in 1968 because his distinct southernness didn't appeal much to voters there. He did exceptionally well in parts of Northern states where there was a large population of Southern migrants, but that wasn't the case in New England and even less so in Maine.
2. Wallace also performed somewhat well in White ethnic rust belt areas as well as far-right bastions in Idaho and Montana. Maine doesn't fit into either camp, despite also being blue-collar and having White ethnic places like Lewiston. Racial tensions didn't exist the same way as they did in the Detroit or Gary area for instance.
3. To a lesser extent than the other two, having native son Edmund Muskie as the Democratic VP choice may have shifted a few voters towards Humphrey instead of Nixon or Wallace.