One of the cruel and ruthless things a predecessor can do to this successor is to claim that the successor was his second choice.
Lee Kuan Yew (picture, left) did it to Goh Chok Tong in Singapore and now Tun Mahathir had emulated by doing it to Abdullah.
This is indeed, on prime facie, a shrew way to exonerate the predecessor from the blame of picking the wrong successor. He can easily say that "after all, he is my second choice. I should have picked the first choice who can do better but I cannot undo it now".
Only God knows if it is true.
Nevertheless, it also has a smack of feudalism and authoritarian. In a mature democracy, the supreme leader should be selected either by consensus or by the majority through election. No one, however influential or great he were to be, should be the sole authority to decide the successor.
When a predecessor-to-be expects his successor-to-be to be grateful to him upon being selected, that is the moment cronyism sets in.
Having leaders with such mindset, our democracy has a long way to go.