Care to cite any such "disavowal" dated before 1997? Even Byrd didn't make that claim: you are. Byrd's remarks in his 2005 book indicate he became "disinterested" in the Klan. "Disinterested" and "disavowal" are two different words with significantly different definitions, and 2005 is not 1950 as you are so willing to confuse to suit your purpose.
Originally Posted by I B Hankering
disavow - deny any responsibility or support for
The quote
"After about a year, I became disinterested, quit paying my dues, and dropped my membership in the organization. During the nine years that have followed, I have never been interested in the Klan."
I think it is pretty clear that, by stopping paying his dues and not working with them anymore, he stopped supporting them.