After every decennial census, there is an opportunity for the state party in power to redraw the boundaries of its voting districts to strengthen its position for the next ten years. There are myriad strategies: contain your opponents so they always win one seat, never more. Dilute your opposition so they never win a seat. The result is tortuous boundaries that defy any other explanation.
These strategies include strange combinations of urban, suburban, and rural districts whose commonality is invisible to all except the person drawing the new lines. Every redistricting brings with it a partisan fight and not infrequently a court battle, too. The next one is Gill v Whitford. There is an alternative, though.
Statisticians use a technique for data analysis called agglomerative clustering. The same technique could be used for the design of voting districts.
Start with a map that describes where each voter lives. Find the two closest neighbors and mark the spot midway between them. Mark the spot with a two and remove the voters from the map. Look again at the map and find the two closest dots. Repeat the procedure. When one spot is a single voter and the other dot is a two, the new dot will be a third of the way from the two to the singleton. Repeat the process until a dot represents 700,000 voters. That is a new district for the House of Representatives. A computer has to repeat the process 230 million times and it must respect state boundaries. That’s a technical problem we leave to the programmers. A personal computer can do it – not quickly, but the results will be the same no matter what computer one uses.
The result of agglomerative clustering would be that neighbors vote in the same congressional district. Insofar as the algorithm is applied equally to every address in the country, it will be equally fair or unfair, depending on your point of view.
At the first election after this new method is employed, we’ll know who was best at gerrymandering in the past – whichever party loses the most seats. After that, it’s up to each party to develop a patform that appeals to neighbors, not to an artificially constructed set of districts.