Not exactly pro-Nazi, but I found the book Hitler's True Believers by Gellately to be quite illuminating on why people found parts national socialism to be quite appealing.

For why Southerners felt threatened before the civil war, you may consult "A Disease in the Public Mind" by Thomas Fleming and "The Road to Disunion, Volume II" by William A. Freehling.

Not exactly pro-Nazi, but I found the book Hitler's True Believers by Gellately to be quite illuminating on why people found parts national socialism to be quite appealing.