For six days, there was no Caliph to take care of the Islamic State. The rebels had plundered and pillaged the public treasury. And it was about time, the Hajis were returning.
The rebels knew the citizens wouldn’t let them go easily after they had murdered their Caliph. They went to Ali and asked him to be a Caliph. he reluctantly refused at first, but after many cries he finally agreed on one condition that was the close companions accept him too.
It is also to be noted that Ali largely had support of Egyptian rebels, while Kufa and Basra had their own preferences in Zubayr and Talha. But Egyptians had numeric majority and they had also led the rebellion.
It is said that Talha and Zubayr were reluctant to accept Ali but had to under pressure from rebels.
But the election was controversial since the ones who killed the last Caliph elected new ones. This opened Ali to new allegation that if not himself directly involved he was an accomplice in Usman’s murder.
Of course, Umayyad clan paid no homage at all. All of them that resided in Madinah fled to Kufa, Basra, Makkah or elsewhere.
It is said that Ali had been claiming the Caliphate on lineage that few Arabs also hated the idea.