There are three statistical tests that are commonly used to assess whether political districts have been gerrymandered: the efficiency gap, the mean-median and the t-test. All these tests have their own limitations and cannot by themselves prove definitively whether gerrymandering occurred. They are useful, nevertheless, in identifying possible cases of it.
When these tests are applied to the election results from the district maps drawn after the 2000 and 2010 censuses in Michigan, a clear partisan advantage for Republicans appears. Republicans held majority control in the Legislature when those maps were drawn.[20]
The redistricting process contained in Proposal 2 may be a better safeguard against potential gerrymandering than the status quo. That is because it creates a separate commission and requires it to draw boundary lines that are supported by commissioners who self-identify with neither major political party.
As described above, the state Supreme Court has said the redistricting process contained in the Michigan Constitution violates the provisions of the U.S. Constitution. Consequently, Michigan has no constitutional rules to guide redistricting efforts. Further, because current legislators cannot restrict the action of future ones, statutory rules for redistricting are not binding on the legislature that gets to redraw the maps. The only rules the Michigan Legislature must follow are those contained in the U.S. Constitution, federal laws and U.S. Supreme Court case law, and the only recourse voters have to challenge the legislatively drawn maps is to sue in federal court.
Proposal 2 would replace the redistricting process in the Michigan Constitution — now a dead letter — with a new one. This may provide more stability to the redistricting process, make it easier for voters to understand how it works, and potentially reduce the number of legal challenges to the redistricting process.
The redistricting process envisioned by Proposal 2 includes important requirements for public transparency. For instance, the commission must hold at least 10 public hearings and accept for consideration plans submitted by the public. The commission must also publish any plans it is considering, hold another five public hearings regarding these plans and allow the public to submit comments for a period of 45 days. Further, the commission must conduct all of its business in meetings open to the public.
It is said that transparency is the best disinfectant for political corruption, and Proposal 2’s emphasis on a transparent redistricting process may help guard against gerrymandering.