Why is the driftless area of Wisconsin so [relatively] Democratic?

[Southern Senator North Carolina Yankee]

fyi driftless isn't ancestrally D.

Its history since Truman
Eisen twice along with Nixon
Did vote for LBJ of course
Strongly nixon in 68 and 72
Carter made some small inroads but not much
Became more R in 1980
Was still republican in 84 although not deep red
Dukkakis won it and it was D since then until 2016.

The farm crisis turned a generation of voters there to the Democrats, kind of like Iowa.