Is it permissible for the Ummah to oblige the Caliph to specify a term limit for his rule upon pledging allegiance to him?

We do not know of any evidence that prohibits setting a presidential term limit for an elected president, because the basic principle in non-devotional matters is continuity, and an elected president cannot be analogized to a legitimate Caliph. The current president is bound by the constitution and can be removed without bloodshed. Stipulating conditions for the president before his election is not considered a deviation, because the benefit lies in capable individuals assuming the presidential task. However, it must be noted that some candidates may hold ideas that are unacceptable to Islamic law. Therefore, those working for Islam must guide the people and clarify the truth for them.