Once every decade, new voting districts for Congress and state legislatures are redrawn.
That's why declines in Michigan's overall population and an exodus of minority voters to the suburbs, coupled with a Republican-controlled state Congress, created new districts that pit Democrat lawmaker against lawmaker.
The creatively-drawn districts pit eight incumbent Democrat legislators into just four districts of Wayne and Macomb Counties. The 13th and 14th districts in Metro Detroit were also redrawn to, by law, guarantee a majority population of minority voters.
The redistricting will have the most effect on non-white Democrat lawmakers. As many as 35% of Michigan's minority sitting state Congressmen could be voted out of office on Tuesday.
Confused about the issues? Head to publius.org, a nonprofit voter education site built by Detroiter Vince Keenan. Publius, an interactive voter guide, custom builds sample ballots and gives voting locations for Michiganders who are registered to vote. Plus, it gives voters their sample ballot, delivered alongside videos and websites and candidate surveys so you can make an informed decision.
To compare the new redistricting map with the current districts, move the slider from right to left.
Find out more about some of Michigan's most contentious races below:
Michigan Primary 2012
Infographics by Jake Bialer, with demographic and district border data from Data Driven Detroit and the state of Michigan.