Michigan’s open primary system allows voters to cast ballots in either party’s primary, but a ballot is considered “spoiled” if it includes votes for candidates from both parties. The city of Farmington Hills, where a state Senate race was decided by 117 votes in the August 2014 primary, had 529 ballots rejected because they contained votes for both parties. This continued a trend in the city: 434 ballots were spoiled in the 2012 primary and 618 in 2010.
Oakland County, where Farmington Hills is located, had 5,666 spoiled ballots due to multiparty votes in 2014. The county clerk estimates that 6 to 8 percent of all ballots in the county are spoiled in a typical primary and that most of those are absentee ballots.
Michigan’s primary ballots include candidates from both parties along with instructions telling voters to vote for only one party.
If a ballot cast in person is spoiled, the optical scanner that tabulates the votes will catch the error and a poll worker can give the voter the option to cast a new ballot. But absentee voters do not have a way to correct a spoiled ballot. In these cases, the votes for both parties’ primary candidates are rejected, but any votes for nonpartisan races and proposals are counted.