Mich. Comp. Laws § Article V § 21: State elective executive officers; term, election.

Sec. 21.

The governor, lieutenant governor, secretary of state and attorney general shall be elected for four-year terms at the general election in each alternate even-numbered year.

The lieutenant governor, secretary of state and attorney general shall be nominated by party conventions in a manner prescribed by law. In the general election one vote shall be cast jointly for the candidates for governor and lieutenant governor nominated by the same party.

Vacancies in the office of the secretary of state and attorney general shall be filled by appointment by the governor.