Out of curiosity, I looked at an old election thread here. There the OP who was co-ordinating the nominations posits:
I think we can all agree that self-nominations should be prohibited.
But, recently, the policy has been:
All nominations are by definition self-nominations. Nominating others is absolutely not supported.
I am not questioning the policy; I am just curious about the reason for the change of heart. It seems that the older elections in stackoverflow also supported nominations by others.