The column below reflects the views of the author, and these opinions are neither endorsed nor supported by WisOpinion.com.
“No matter, no matter what color, umm, you are still my brother” – Timmy Thomas from “Why Can’t We Live Together?” (1972)
Bad blood continues to stymie Blue and Red from redistricting détente even though the competing bills, 2021 AB395 and 2023 AB415, are strikingly similar. Fortunately for us the redistricting standards set by both parties have enough common ground to leave the mapping to us, the people, and not the Legislative Reference Bureau.
Both bills can be applauded for providing more clarity to redistricting standards for legislative maps. Each reaffirms the Wisconsin Constitution in demanding that districts be compact, and their boundaries coincide with ward boundaries. Both bills require the preparation of the redistricting plans be nonpartisan, specifically barring the use of the residence addresses of incumbent legislators, the political affiliations of registered voters, previous election results, and demographic information except as necessary to meet the requirements of the Voting Rights Act. Most significantly, both bills codify the traditional redistricting principle of preserving county and municipality unity by stating that “the number of political subdivisions divided among more than one district shall be as small as possible.”
The standards of the two bills do differ in three significant ways. 1) The Dems essentially demand each district be within 5% of the ideal population whereas the GOP narrows that margin to 1%. 2) The GOP bill measures district compactness via the Reock metric, ratio of the area of the district to that of the smallest encompassing circle, while the Dems compactness measure takes over a dozen paragraphs to describe. 3) The GOP’s bill supports a previous court ruling that a district containing [all] detached portions of a municipality is deemed legally contiguous even if the area around the detached portion of the municipality is part of a different district. The Dems’ bill is moot on this point.
Given that for the last five redistricting cycles Assembly maps have met the GOP’s stricter population equality requirement, it seems reasonable to continue this practice in the future. The GOP’s decision to measure compactness with the Reock metric is much simpler and less complicated. The Dems should have no problem accepting the Reock compactness metric and what the courts have already determined to be a reasonable treatment of municipal “islands.”
Thus, the Assembly redistricting map problem presents itself. Find an Assembly map in which the population of none of the districts strays from ideal more than 1% that minimizes the number of split counties, cities, villages, and towns.
The compactness condition curtails wholesale “cracking” of partisan populations, as was done in 2011. The Wisconsin Constitution gives guidance here stating that each Assembly district be “as compact as practicable.” That is, the mapper should try to maximize compactness while minimizing splitting.
One simple way to combine these two ideals into one is to consider minimizing the quantity, number of political subdivision splits divided by the average Reock compactness of the map. By minimizing this ratio, one satisfies both goals at once. The ratio also provides a simple test to compare competing maps. Whichever map has a lower Splits/Reock ratio wins. If other requirements are met (VRA satisfaction, absolute deviation of each district less than 1%, contiguity, and numbering the Assembly districts so Senate districts can be properly nested) there should be no debate as to which map is the best. If other communities of interest need to be kept intact, adjustments can be made to the winning map.
If the Legislature is serious about public-informed, transparent, redistricting map selection, why not reopen its portal for a month and invite anyone to submit an Assembly map? This time, however, the Legislature needs to actually look at what is submitted. Maybe even run a contest. The Legislative Technical Services Bureau can publish and perform the analyses just like it did before with the Draw Your District portal. May the minimal Splits/Reock ratio win. No politics, no lawsuits, just maps.
— Don Leake of the WI Map Assessment Project is a retired UW-River Falls math professor.
