In total, 78 of Michigan’s 83 counties appear to have more registered voters than residents of voting age...
The largest county in the state, Wayne County – where the city of Detroit is located – has only 1.3 million residents of voting age, but 1.4 million registered voters, according to data from the U.S. Census.
Another example is Genessee County, with 351,000 registered voters but less than 300,000 residents.