Buchanan points out that this makes legitimacy a more fundamental normative concept than authority. Instead, it is argued, it is sufficient for political legitimacy if all can agree that a particular decision should be made, even if they disagree about the reasons that support this decision.
Appiah, Anthony, According to Kant, coercion is part of the idea of rights.
Public reason accounts tend to focus on the problem of justifying political coercion. This problem arises when the evaluation of alternative outcomes is logically connected to a set of independent premises. Cambridge: MIT Press. If people believe that existing political orders or laws are appropriate and worthy of obedience, then those orders and laws are legitimate.
This requirement includes a demand for minimal democracy. Such a state would be legitimate.