Islamic legal opinion on governance-power relation (From 11th to 19th century)

The contract of governance (Contract of Imamate) under Islamic law is defined as "the contract out of mutual consent and election, without any force and coercion". This definition allows us to differentiate between the features of a legitimate authority and despotism. And the fact that those, who are qualified to appoint or depose a caliph or another leader on behalf of the Ummah, the so-called "Ahl al-hall wal-aqd", are regarded as the protectors of/guardians over the Contract of Imamate, gives an idea of where the governance derives its power from. In fact, the most important questions that need to be answered within the context of the legitimacy of the leadership are the following: Who represents the political will of the Ummah, which is the constituent element of the contract? Which section of the society holds the power? Or briefly; what, where, or who is the source of the leadership's power? Nonetheless; every form of governance depends on the exercise of power in order to gain authoritativeness for its implementations, validity for its sanctions, and to ensure its continued existence in the face of internal and external threats. Do the mutual pledge of allegiance (Bey'at) and the exercise of power by the governance constitute the incompatibility of theory and practice? Or; is it possible to evaluate the practical organization of governance in the history of Islam while adhering to this framework of theoretical legitimacy? These issues will be examined carefully with reference to the opinions of Islamic jurists, who diligently emphasized the fact of power in their works, since the 11th century.