On his part...
On his part, it was a gesture of reconciliation but it did not mitigate their hostility to Islam. But Muhammad, the Messenger of God, had not been dead long when Abu Bakr elevated these traditional enemies of Islam, and the dynastic foes of its Prophet, to the highest ranks in the army. He made Yazid, the son of Abu Sufyan, a general in his army. When Syria was conquered, Umar who had succeeded Abu Bakr as khalifa, made him (Yazid) its first governor.
Yazid died a few years later whereupon Umar made his younger brother, Muawiya, the new governor of Syria. As if he had not done enough for the Umayyads, Umar, on his deathbed, manipulated the situation in a manner that guaranteed the succession of Uthman, another Umayyad. In the caliphate of Uthman, the members of his clan, the Umayyads, were ruling every province in the empire and they were commanding every division in the army.
The Ansar also feared that if the Muhajireen seized the government of Medina, then they (the Muhajireen) would belittle their (Ansars') services to Islam, and would relegate them to play a minor, if any, role in Islam. Gifted with prescience as they were, the Ansar had made a correct and a realistic assessment of the situation. Their assembly in Saqifa was purely defensive in nature. It was prompted by the sheer instinct for survival. But unfortunately, they were dogged by their own jealousies.
Their jealousy caused their aims to be miscarried. Their tribal components – the Aus and the Khazraj – were suspicious of each other, and it was this suspicion that gave them away to the Muhajireen. As already noted, the action of the Ansar in gathering in Saqifa is open to question, but their instinct was sound. The subsequent events amply proved that they were right and justified in questioning the intentions of the Muhajireen toward them.
Among the Muhajireen, the only protector of their interests was Ali ibn Abi Talib. But when the Quraysh succeeded in blackballing him from power, they also succeeded in downgrading the Ansar to a mere rank-and-file status. When Muhammad died, and Ali's succession was precluded, the Ansar ceased to be the masters in their own home – Medina! Previous…