This applies for one of his Congressional runs:
An Old School Republican who became disgusted with the GOP's stance on social issues sometime during the Reagan era and didn't see Sander's economics as being as big of a problem.
Likely a single issue voter on some issue Congressional Sanders differed with their GOP opponent, who has kept this view for at least 60 years. My guess, Trade, New England was pretty Protectionist in the early 20th century, so I assume this voter was a single issue anti-Free Trade Voter in Vermont.
I was thinking that civil rights made more sense than protectionism but I can see it both ways.
I can see the reasoning for that. I just don't think civil rights was that major of an issue in 1924 and one of Sanders' congressional races to have a likely single-issue voter over that. I think trade is an issue that overlaps better with both of the candidates and their eras.
Especially since Coolidge was not exactly great on civil rights and outright terrible (from my perspective) on immigration.