The challenge to Mr Mugabe's rule from factions within the ruling party has dissipated in recent months.
Jonathan Moyo, Mr Mugabe's former information minister and now an independent MP, says two Zanu-PF groupings - one led by Rural Housing Minister Emmerson Mnangagwa and the other by Vice-President Joyce Mujuru - have been publicly supporting Mr Mugabe's endorsement as presidential candidate.
Yet, only a few months ago, Mr Mnangagwa and Mr Mujuru had both been seen as possible successors should Mr Mugabe have been persuaded to leave office.
"Behind the scenes, there is widespread disgruntlement," says Mr Moyo.
"There is a rude awakening that Mugabe will not step down voluntarily, and there is nothing that can be done, using party procedures, to deal with his succession."
Eldred Masunungure, a political science lecturer at the University of Zimbabwe, says the rival factions within Zanu-PF have to regroup.
"They've been overwhelmed by the Mugabe wing, but they lacked the wherewithal to reverse what was a fait accompli [Mugabe's endorsement].