Surely it is time for "decent" members of the ANC to realize that ANC now stands for A Nasty Crook, and by staying with the party they are supporting a structure which is bringing South Africa to the joke status the rest of free Africa had 20 years after independence.
Some of them are charismatic politicians with significant followings.  They need to find a new party, either existing (admittedly difficult for anyone raised on "struggle" milk,) or create one.
I doubt they will though, the lure of the grave train is too strong, and their theme song is "Baby, it is cold outside..."