Even when it is agreed that magistratical power is ordained of God, as Paul says in Romans 13, there are various theories as to how that power is applied to any particular individual in office. Is they king (e.g.) appointed immediately by God, or mediately by the people? George Buchanan famously advanced and argued for the latter theory, what one might call the “bottom-up” approach, where the power of appointing individuals to office flows from God, down to the people, and back up to the one installed in office.
Samuel Rutherford, too, makes the case for this position in Lex, Rex, Question IV. Rutherford makes the important distinction between the office of magistrate and the individual(s) who are placed in it. That there should be an office of magistrate comes immediately from God, by a secondary (not primary) law of nature. 1 But who in particular is to fill that office comes from the election 2 of the people. Interestingly, he draws a parallel between mundane office and ecclesiastical office in this respect: both, as offices, are ordained of God; but the particular individuals who are to fill mundane and ecclesiastical office receive their position from the choice of men.
Whether the king be only and immediately from God, and not from the people.
That this question may be the clearer we are to set down these considerations: —
1. The question is, Whether the kingly office itself come from God. I conceive it is, and floweth from the people, not by formal institution, as if the people had by an act of reason devised and excogitated such a power: God ordained the power. It is from the people only by a virtual emanation, in respect that a community having no government at all may ordain a king or appoint an aristocracy. But the question is concerning the designation of the person: Whence is it that this man rather than that man is crowned king? and whence is it — from God immediately and only — that this man rather than that man, and this race or family rather than that race and family, is chosen for the crown? Or is it from the people also, and their free choice? For the pastor’s and the doctor’s office is from Christ only; but that John rather than Thomas be the doctor or the pastor is from the will and choice of men — the presbyters and people.