Compiled Laws, Chapter 168. Michigan Election Law § 168.42

Sec. 42. In the year in which presidential electors are to be elected under section 43,  1 each political party in this state shall choose at its fall state convention a number of candidates for electors of president and vice-president of the United States equal to the number of senators and representatives in congress that this state is entitled to elect. The chairperson and the secretary of the state central committee of each political party shall, within 1 business day after the conclusion of the state convention, forward by registered or certified mail a certificate containing the names of the candidates for electors to the secretary of state.The candidates for electors of president and vice-president who shall be considered elected are those whose names have been certified to the secretary of state by that political party receiving the greatest number of votes for those offices at the next November election.