Answer:"Republic" is often assigned to governments that are founded on the majority of people, that is, the government relative to majority. Republic in its western concept is different from its Islamic one. In its western meaning, republic means the legislation of public government that is people give the right of authority to someone, directly or indirectly and place a person as the president to manage the society. In this case people themselves are legal and the legislation of the government and the authority is certainly done according to people's choices. Therefore, the origin of power is, in its essence, from the public.
However, in Islam perspective, the right of authority only belongs to God and those who are authorized from God. Therefore, the authorization of the government and the authority is divine and not public. However, the entire stages of Islamic government which is interpreted as "the authority of God on people" would not be practiced until people accept it.
Therefore, the republication in it Islamic concept means the public acceptance. This is the same interpretation of "presence of the present" in Imam Ali's words who believes it as the cause of his project and the acceptance of the government by people. Thus, Islam believes that the objective achievement of the divine government is based on the acceptance, selection and cooperation of people and also believes in its divine authorization.
The concept of selection is equivalent to the concept of allegiance in the history of Islam. There are a lot of instances of the mentioned issue in history. Principally, the meaning of allegiance in Islam is the same public choice which interprets the meaning of republic.
Therefore, this kind of Islamic republic means the gathering of choice and the mixture of the divine and public powers and not the cause of weakness in divine and public responsibilities.