In the leadup to the Civil War, you had one party enthusiastically embracing evil (Democrats then, TrumpGOP now) and the other party refusing to meaningfully oppose it (Whigs then, Democrats now).
The Whig leadership repeatedly decided to betray their abolitionist supporters, on the basis that they had nowhere to go while the Democrats were loudly endorsing slavery.
You’ll note that it wasn’t the “embracing evil” party that was destroyed and replaced. Evil will always find a fan base, but everybody hates a Quisling.
