Did the Prophet, peace and blessing be upon him, entrust the Khalifa to Ali?
Answer:
It has not been established that he entrusted him with it. He, (the Prophet) peace and blessing be upon him, made it clear with many evidences that prove that the one who was deserving of the Khalifa was As Sadeeq. (Abu Bakr) He appointed him to lead the people in prayer. And He said, ALLAH and HIS Messenger have refused everyone except Abu Bakr. And the Companions have agreed upon the Khalaafa (Rule) of As Sadeeq (Abu Bakr) And Ali, may ALLAH be pleased with him, gave him (Abu Bakr) the pledge and he was pleased with him, according to the consensus of the Companions. So Ali, may ALLAH be pleased with him, was from those whom were in agreement with Abu Bakr being the Imam, and Khalifa, and he (Ali) assisted him and worked with him. May ALLAH be pleased with them all.
Answer by Imaam 'Abdul-'Azeez Ibn 'Abdullaah Ibn Baaz [d. 1420] (rahimahullaah)
Translated by Rasheed Barbee
Source: http://www.sahab.com