Michigan’s independent redistricting commission is hearing public comment this week. You can comment to support maps others have proposed, or present your own map. See Peregrine Kate’s post for more details on public comment.
I think I will support a map created by someone else. But… how do I draw a map if want to do that? My Google search for “gerrymandering software” gave me DistrictBuilder.org as the first result. It’s a free and open source program.
It looks good. I’ll give it a try. District Builder is a “Web app,” meaning you can use it in your JavaScript-enabled Web browser. After signing up, you can get a tutorial that explains the basics of the software.
Then, to make your first map, choose the area to redistrict. I chose to give it a try with Michigan’s districts for the U. S. House of Representatives.
Your objective: build 13 districts for Michigan, each with a population of 775,179. Use DistrictBuilder to group counties, blockgroups, and blocks into districts.
With the data loaded, I can start the process by choosing counties to be District 1. Currently District 1 includes Michigan’s entire Upper Peninsula. I think that’s fair. So I started clicking on the Upper Peninsula counties to add them to District 1.
But we’re also going to need some of the northern Lower Peninsula to get anywhere close to 700,000. When you like how District 1 has shaped up, click “Accept,” which saves the changes so far and maybe moves you on to the next district (it’s not always clear which district is selected).
The tutorial recommends starting with at the county level, likening it to painting with a broad brush. Then you can fine-tune later with blockgroups or even blocks. But you should drill down to blocks only if absolutely necessary.
I feel that if two neighboring districts, neither of which includes one full county, cross the same river or the same major freeway twice, the map is automatically suspect.
The DistrictBuilder user interface is not as clear as I would like. It seems that you must click “Accept” before you can move on to another district. Otherwise you might get confused by a non-contiguous district warning. I know I did.
Looks like the only way to temporarily remove areas from any district is to assign them to the so-called “District 0.” I wasted a lot of time clicking pointlessly.
I was able to assign the first eleven districts along county lines for all Michigan counties except Wayne County. But for the tri-county area of Wayne, Oakland and Macomb, it’s absolutely essential to switch to selecting by “blockgroups.” I will have to tweak Oakland and Macomb by blockgroups.
Clearly at this point it’s not a map I would want to present to anyone. I tried to stick closely to the current districts (which is not easy because Michigan’s going down from 14 districts to 13) so as to get a better idea of what a difference impartial redistricting makes.
What I’ve got thus far gives Democrats only two House seats with two House seats unassigned. So potentially four seats out of thirteen. Which is worse than the current map, as that one splits the House seats evenly between Republicans and Democrats.
But I’m only getting green checkmarks for three districts (I chose a tolerance of ±5% from 775,179). This means I must adjust pretty much all the other districts to get them to be reasonably close to each other in population.
I was actually starting to get a headache trying to balance the districts. So I decided on a different strategy, after un-assigning everything: first apportion Detroit between two districts, then try to draw other districts around the other big cities of the Lower Peninsula. Then whatever’s left can join the Upper Peninsula in District 1.
Now I’ve got green checkmarks for all thirteen districts, but this is not a map I really want to present to anyone yet either. I will show you a low-resolution screenshot, though:
This gives nine districts for Republicans with Cook PVI ranging from R+2 to R+14 and only four for Democrats ranging from D+7 to D+38. And Flint is in an R+2 district? I must have taken a wrong turn at Albuquerque...
I definitely need to work on this map a lot more. Despite not having the telltale signs of gerrymandering, it still feels like it hews too closely to the current partisan gerrymander.
DistrictBuilder has an Evaluate feature. I clicked on it and it says my current draft meets the requirements of equal population and contiguity. The optional metrics are:
- R+1 average competitiveness (if I’m understanding correctly, the ideal theoretical ideal would be R-0/D-0)
- 50% compactness (I’m guessing closer to 100% would be better)
- Only one majority-minority district (more would be better, right?)
- Five county splits (the fewer, the better, I think)
Even if I don’t get this map to a point I like, it still has been quite an educational experience.
For the price, DistrictBuilder looks very good. The “professional” gerrymandering software packages that consulting firms sell to the political parties probably have a hell of a lot more features, such as
- The ability to start off from the current districts adjusted for an increase or decrease in the number of districts
- The ability to start from what I call a “clean” map (in which the computer obtains maximum compactness without regard for party affiliation or other demographic factors)
- The ability to select an entire city at once
- The ability to select anything not already assigned in a given county
- The ability to play around with historical data (e.g., if you want to do a different gerrymander of Texas for the 1990s).
- Also nice would be the ability to renumber neatly and easily by swapping (e.g., if I want District 5 and District 6 to swap numbers)
Even so, DistrictBuilder is a pretty good tool for giving ordinary citizens an idea of what sort of considerations go into redistricting. I would recommend schoolteachers give their students an assignment of drawing districts for the state they live in.
Of course even with the best tools, redistricting should not be done in a hurry. If I really wanted to present a map I made from scratch, I would feel I need several days after executing my initial conception to ponder the map I create, even if I wind up making no changes. But time’s running short for public comment now...
That’s why I definitely won’t be presenting any map I create from scratch. If I present any map, it will be one that is a tweak of a map created by someone else. Drawing my own has certainly helped me understand the balancing act that’s needed here.
Thursday, Sep 30, 2021 · 3:49:15 AM +00:00
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Alonso del Arte
Peregrine Kate has some important updates, and hopefully a headline that will convey the urgency better: ”Ready to cede control of the MI House to the GOP until 2032? Yeah, me neither”
Michigan is a state that has consistently sent two Democrats to the U. S. Senate for the whole time I’ve been a voter, yet Republicans control the state legislature? It’s only because of gerrymandering.