I doubt this "group" voted for Reagan over Carter, look at the county results for 1980. Reagan barely won the Southern states that he did win, and his strength came from the more populous counties. Carter won all the rural, Dixiecrat counties.
Blacks.
He lost several rural counties which had to be mainly White...
White : Reagan 50, Carter 45
Black: Carter 90, Reagan 10
would be enough to win any Southern county for the Democrats.
Also, Reagan won the White South 60-35.
Reagan won Lincoln haters.
All I said is that Carter won most of the rural voters while Reagan won the more suburban counties. I'm going to go out on a limb and guess that your classic Dixiecrat type Lincoln hater is more common in rural counties rather than booming suburbs that have larger populations of Northern transplants. Considering Reagan only won White voters by 5, it would not be outrageous to claim that Carter might have won "Lincoln haters."