My ancestors were Southern Unionists, and we've been Republicans since the Civil War!
There were many Southern Unionists, though most people don't know this. I read somewhere that every seceded state (aside from South Carolina) had a substantial Unionist population.
BTW, when New England was threatening secession in the days of the Essex Junto and the War of 1812, Southerners called them "traitors."
That's actually pretty funny and completely believable knowing what I know about human nature.