Algorithms cure Gerrymanders, but politics remain

With the midterm elections just weeks away, Californian politicians have had to scramble more than usual to compete in redesigned districts. The new neighborhood boundaries are the product of theCalifornia Citizens Redistricting Commission 2020which was formed to eliminate partisan politics from being a factor.

However, partisan politics isn’t really the issue in California, since Democrats have wielded near-absolute political power in the state for nearly 30 years. So why are the final district maps so twisted?

Take a look at California’s new US congressional districts, using an image from the final map page on the California Redistricting Commission website and shown below. Unfortunately, because the contortions are so complex, the image only shows neighborhoods in the Los Angeles area. Do these neighborhoods follow logical geographic lines or are they a little twisted?

Congressional District 42 is a prime example of a district drawn in defiance of logic. Its southern end is at Long Beach, but as it expands northeast it thins into a ribbon to absorb a slice of Lakewood and Bellflower, then widens out a bit to incorporate parts of Downey, then bends northwest to take Huntington Park at its northern end. What machinations made it possible to define CD 42? It didn’t make sense.

The CD 45 is curved in the same way, but in an inverted arch. It starts south at Fountain Valley, then moves northwest to take Westminster, then back northeast to accommodate Buena Park, then continues east to grab parts of Yorba Linda. Across Los Angeles and throughout the state, examples of pretzel-shaped neighborhoods abound.

There is another way to shape the districts that our politicians represent. The ability to use algorithms that manipulate constituency-level geographic units to shape districts with equal numbers of residents and logical boundaries is well established. Several resources readily available online document this: mathematics thesis 2021 “Repairing Redistricting: Using an Integer Linear Programming Model to Optimize Fairness in Congressional Districts” is an example that deigns to explain its concepts in plain language. Other good references can be found hereand here.

A 2022 study published on ScienceDirect titled “An Algorithmic Approach to Legislative Allocation Bases and Redistricting” is also readable and discusses some of the challenges, as well as how software developed over the past few years can address them.

For example, when directing an algorithm to iterate a set of district boundaries while maintaining equal populations and solving convex edges and minimizing the cumulative length of the polygons formed by the districts, the user must specify the initial geographic centers of each district. With several possible solutions, this placement affects the results. While the latest software handles this challenge well, automatically moving centers as it moves toward a solution, one would think that defining centers is a subjective choice that could be left to a nonpartisan commission. After all, geographic district “centers” should mean the downtown areas of major cities.

At all levels, geographic logic eluded the California Redistricting Commission, as evidenced by this map of the new California State Senate districts.


In the Los Angeles area, SD 34 is a prime example of illogical boundaries. It begins in Santa Ana, travels north to Anaheim, marches northwest through Fullerton, then northeast to culminate in La Habra, while adding, across an isthmus of to barely 500 feet wide, a peninsula of constituents in the neighborhoods of Colima and Leffingwell.

These gyrations – look at SD 30 and SD 22 before turning away from the map above, bearing in mind that the entire state is just as weird – aren’t necessary. In a 2019 article “Automated Congressional Redistrictingthe authors describe “swapping algorithms” that swap voters by swapping boundaries to streamline the shape of constituencies while maintaining the same populations in both constituencies. This can be part of the iterative process. Why, for example, wouldn’t SD 30 absorb the neighborhoods of Colima and Leffingwell from SD 34, while SD 34 reclaimed the absurdly artificial peninsula of SD 37 in North Fullerton, while SD 37 took grabbed portions of Rancho Santa Margarita from SD 38, and soon?

The answer is not in the wind. It is vested interests, even in this one-party state, that are clamoring for constituencies in which they believe they can control elections. Take a look at champion mutilated district boundaries, the California State Assembly:


As for the new California State Assembly districts, almost every one of them has ridiculous boundaries. Not only are they all so crazy you can barely tell where one begins and the other ends – ref. AD 54, 62, 64, 65, 67, 73 – there is an abundance of inexplicable micro-displacements of ward boundaries, where a single street juts out into another ward.

For example, AD 67 pulls a finger west in AD 70 on Pacific Avenue, and only Pacific Avenue. For some reason, 16 houses on the south side of Pacific Avenue are in 67 AD. The houses on the north side of this street are 70 AD, as is the Union Pacific property just south of their back fences. Why?

This is found everywhere. A few blocks north, six properties on the west side of Magnolia Avenue are part of AD 70, entering AD 67. To the east, five properties on Gylah Lane are part of AD 73, entering AD 59. Through the city to the northwest, six properties on the south side of Slauson Avenue are part of AD 64 which enters AD 56.

These microscopic displacements, up to half a street, of the limits are not accidental. They are evidence of retail political haggling that is the obsessive and antithetical opposite of relying on algorithms. Or to be more precise, the algorithms were used extensively in this exercise down to the atoms in what was supposed to be a disinterested recutting process, but not the right algorithms.

The home page from the California Redistricting Commission provides a clue as to what really happened when these boundaries were drawn. There are 11 photographs, all lined up, each with a portrait of someone who is part of a different identity group. This is a diverse and inclusive homepage layout, which is a lofty and laudable ideal. Why not? Put everyone in the picture. But the way that translates to district boundaries isn’t so pretty.

What the California Redistricting Commission wanted to ensure, and I hope it was done with more decorum than what was recently displayed by a suddenly infamous threesome in Los Angeles, was to ensure that there was proportional representation, primarily by ethnicity. Getting proportional representation for the GOP was not a priority because the GOP has no power.

Ethnic voting blocs, on the other hand, have a lot of power, at least until they don’t. Democrats want to make sure they create districts that allocate seats to their designated power brokers in Hispanic, Black and Asian communities. Because these communities are still reliable Democratic voters, this is a sound political strategy.

The day may come, however, when ethnic voters are as politically fragmented as white voters. It will be a very good day for California, as it will mean issues that transcend race, affecting everybodywill matter more to voters than the Democratic mantra about how disadvantaged they are and compel Democratic politicians to protect them.

If that happens, nothing should stand in the way of partitioning the Congressional, State Senate, and California State Assembly districts into something resembling a checkerboard, instead of a jigsaw .

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Sharon D. Cole