> The KKK was thoroughly defeated as a power in the US thanks entirely to the US system of freedom of speech; the KKK had a very large, potent base at one time. They were not outlawed as a group, sunlight-as-disinfectant overwhelmingly won out

While the Ku Klux Klan Act of 1871 didn't, you are correct, outlaw the Klan as a group, it did authorize a whole lot of measures—including authorizing federal military force and suspension of the writ of habeas corpus, and new federal civil and criminal causes of action—to combat their actions and those of similar groups, and those authorities were liberally used in suppressing them. Describing the successful strategy as “sunlight as disinfectant” rather than massive application of force is... not grounded in fact.