[1]        As a "poll book total" was not kept prior to 1976, the turnout figures for elections held between 1948 and 1974 are based on the greatest number of votes cast for any office in the election.

[2]        A registration figure for the state was not compiled for elections held prior to 1956.

[3]        The large increase in the number of registered voters in the state from 1970 to 1972 was the result of a March 1972 Michigan Supreme Court ruling which declared that it was unconstitutional to purge the registration of a voter who had not voted over a period of two years as Michigan law then required.  In effect, this compelled clerks to reinstate the registrations of "non-voters" who had been purged from the registration roles since 1968.

[4]        The large increase in the state's voting age population from 1970 to 1972 was the result of Amendment XXVI to the U.S. Constitution which lowered the minimum voting age from 21 to 18.

[5]        Two events occurred in 1975 which affected the 1976 registration total:  (1) the Secretary of State Branch Office Voter Registration Program was put into effect in October and (2) provisions allowing for the creation of "inactive" voter registration files were put into effect.  Registration totals listed for 1976 to 1988 reflect only those registrations held in 4-year "active" files.

[6]         The National Voter Registration Act, effective January 1, 1995, eliminated the initiation of any voter registration cancellations for inactivity and introduced several new voter registration programs in the state, including mail-in registration.

[7]         Public Act 142 of 1989 authorized city and township clerks to establish a 5-year voter registration file and eliminate their "inactive" files.  Registration totals listed for 1990 to 1994 are based on the 5-year voter registration files maintained by the clerks.

[8]         In 1998, approximately 600,000 duplicate voter registration records were purged from the state's registration rolls through the implementation of the Qualified Voter File - a statewide voter registration database mandated under Public Act 441 of 1994.