The Shi’ites claim that Abu Bakr and ‘Umar had usurped the caliphate from ‘Ali and conspired against him in order to prevent him from having a hold on it … and other charges.
If this claim were true why did ‘Umar put him among the six members of the Shura he delegated to deliberate on choosing the caliph? Had he removed him the way he removed Sa’id ibn Zaid or had he appointed some other person in his place, no one could have opposed his opinion.
Therefore the unavoidable fact is that the companions surely placed ‘Ali in the right and relevant position he belonged to, without exceeding limits or negligence in that respect, may Allah be pleased with all of them. They have also given their pledge to the rightly guided caliphs in their relevant and respective orders, beginning with the best, followed by the best etc, thereby putting ‘Ali in his most deserved class.
One thing to buttress this fact is that when ‘Ali ascended the throne after the martyrdom of ‘Uthman, the Muhajirun and Ansarwasted no time before pledging their allegiance in respect of the caliphate to ‘Ali and none of them ever apologized to him for their acceptance of Abu Bakr, then ‘Umar and ‘Uthman before him. No one on this earth could claim that such a thing occurred from those pious sahabah. Or did anyone of them ever repent for his rejection of a nass on ‘Ali’s leadership, or did anyone of them ever mention that he remembered a nass he happened to forget in favour of ‘Ali’s Imamate?
..On the day of Saqifah the Ansar contested accepting Abu Bakr as caliph at the initial stage, and called upon everyone to vest Sa’d ibn Abi Waqqas with the post. ‘Ali, on the other side, stayed indoor, neither inclining to this nor to the other group. But in the end the whole of the Muhajirun and Ansar agreed on Abu Bakr may Allah be pleased with all.
This action from the Ansar in particular, i.e. changing their minds to accept Abu Bakr must be for one of three reasons:
1. That they had been coerced into accepting Abu Bakr;
2. That Abu Bakr’s right and eligibility to the post emerged so clearly that they had to submit;
3. That they took that action without any specific reason.
No fourth reason can be thought of here.
So, if the Shi’ites will say that the Ansar were forced to give their pledge, one would necessarily reject that, for it is a sheer lie. Because there was never a battle between the people at Saqifah, nor was there any physical combat or exchange of abuses or threats, and neither was anyone armed. Moreover, it was not possible for the Ansar to be terrorized inside their own home and considering their large population of more than two thousand strong warriors, all from one single clan well known for their bravery, so much so that everyone was weary of launching any attack on them. That is because they had gone through an eight-year war against almost all Arab clans in their surroundings, resulting in them not being afraid of death. Above all that their minds were fresh with their experience in the just concluded war against the Romans in the battle of Mu’tah. It was therefore totally impossible for such people to fear Abu Bakr and just two other men with him, especially considering that Abu Bakr was not from a strong clan, nor did he own many slaves or have strong relatives or wealth. So how could they return to him while compared to them he was of no value. But all the same they accepted him and pledged their allegiance to him wholeheartedly.
It is likewise false to assume that the Ansar rescinded their former decision of vesting one of their kinsfolk with the caliphate while they believe that it was their eligible right to claim so, just for nothing. It is also impossible for the differing inclinations of that large number of the Ansar to agree on something they knew was wrong and void without being forced by fear or intimidation, and without being influenced by their vested interests to acquire some wealth or reputation. How could they wholly sacrifice all that to a man who had neither strong relatives to support him, nor any power or security operatives to guard him, nor had he any palace which he took to be a fortress against any attack, nor strong slaves or wealth and influence with which to acquire whatever he liked and usurp whatever power from whomever he wished.
So, if all the above assumptions are false, nothing then remains but the fact that the Ansar only changed their minds and accepted Abu Bakr radiyallahu ‘anhu for a very strong and authentic proof from the Prophet sallallahu alaihi wa alihi wa sallam,not for a personal ijtihad or a simple assumption like their own.
Having made void the assumption that the Ansar were the right heirs to the throne and the caliphate had slipped from their hands, the question then is, what made all of them agree on denying the purported explicit statement of the Prophet sallallahu alaihi wa alihi wa sallam that ‘Ali would be the imam after him immediately?. It is surely impossible for the views of all of them to agree on helping the same person (i.e. Abu Bakr) that wronged and usurped them of their right, against ‘Ali may Allah be pleased with all of them.
 That is, if there was really any nass, why did the Ansar who had just lost the caliphate to Abu Bakr, having known that the Prophet had plainly mentioned the name of ‘Ali as the Imam after him, agree on shutting their mouths on reminding Abu Bakr of the Prophet’s statement, or how could they have connived with Abu Bakr who had just usurped the caliphate from them, to deny ‘Ali his right? (Translator).