When I was kid, I knew guys in school who had fathers in the KKK. It wasn't so uncommon back then. It wasn't considered to be a really big deal. Of course, they were all fanatical Democrats. One kid even showed me his father's KKK robe.
I'm not sure that being in the KKK is something that you can repent from. To join that group you have to have certain core beliefs, and swear certain oaths. Those beliefs, established in childhood, would be very difficult if not impossible to overcome as an adult.
Once you are in the KKK, you are always in the KKK. It is not something you can just 'quit'.