I would only add to this excellent review that not only was it not ideological but from 1865 to 1900 it was HEAVILY religious. Paul Kleppner did a pathbreaking book showing that you could predict elections based on a dozen midwestern counties of certain protestant religious make-ups.
But as you point out, for the longest time, the Civil War determined everything-—”vote as you shot”.
Utah, for example, voted GOP for the longest time because of Lincoln’s positive treatment of the Mormons during the CW.
“Utah, for example, voted GOP for the longest time because of Lincoln’s positive treatment of the Mormons during the CW.”
Would Buchanan’s ‘Mormon War’ have played a role in their voting as well?