God chooses a king by inclining the people for one above another

"I think royalists cannot deny but a people ruled by aristocratic magistrates may elect a king, and a king so elected is formally made a lawful king by the people's election; for of six willing and gifted to reign, what maketh one a king and not the other five? Certianly by God's disposing the people to choose this man, and not another man. It cannot be said but God giveth the kingly power immediately; and by him kings reign, that is true. The office is immediately from God, but the question now is, What is that which formally applieth the office and royal power to this person rather than to the other five as meet? Nothing can here be dreamed of but God's inclining the hearts of the states to choose this man and not that man." - Samuel Rutherford, Lex, Rex, or The Law and The Prince, pg. 9

The Government that be are from God

"All civil power is immediately from God in its root; in that, 1st, God hath made man a social creature, and one who inclineth to be governed by man, then certainly he must have put this power in man's nature: so are we, by good reason, taught by Aristotle. 2d, God and nature intendeths the policy and peace of mankind, then must God and nature have given to mankind a power to compass this end; and this must be a power of government." - Samuel Rutherford, Lex, Rex, or The Law and the Prince, Pg. 1