Partitioning the Vote

My earlier notion for preventing gerrymandering was not very effective. Looking at the data for the Michigan 2018 election, the Democrats had a majority of the vote but a minority of the districts. My proposed rule would have done nothing to prevent that.

Exactly what a good rule might be, I don't know. It's a difficult problem! But the basic criterion that seems logical is that the fraction of districts won by each party should be roughly proportional to the fraction of votes for that party. A general shift in voter preference should be reflected with a proportional shift in election results, in the fraction of districts won by a party. This would be achieved by having district boundaries drawn so that the fractions of votes for each party across the districts varies across a reasonably wide spectrum.

The challenge with this approach is that the notion of "a general shift" is too vague to be of much use. Still, a simple model can get the idea across.

Here is an idealized situation, a state with ten districts. When the vote is split equally, the range of district results could be:

With a general drift to 60% of the vote for one of the parties, the number of districts won could change proportionally:

A further shift, to 70%, would continue to be reflected in the proportion of districts won:

Against Gerrymandering

The notion of a free market strikes me as oxymoronic. It's like a game without rules. It's nonsense. A game is defined by its rules. Similarly, markets are defined by rules. Of course, good games and good markets have rules that are fair, for example. Finding ways to structure markets effectively is a worthy challenge.

The recent Supreme Court decision, to keep the federal judiciary out of the business of how to draw the boundaries of legislative districts, strikes me as a move in support of a free political market. Why try to figure out what a fair market might look like? Let the market decide what is fair! But the problem with anarchy is that it is impossible. We can decide on rules using methods developed over the centuries and codified by brilliant political thinkers like the framers of the United States Constitution, or we can revert to the cruder methods of tyrants.

Of course the framers didn't provide all the answers. We the people have the responsibility, working with the general framework set out in the constitution, to work out the rules and regulations, the laws and institutions, by which we may prosper fairly and equitably.

It's clear enough that legislative boundaries can be gerrymandered to amplify the dominance of whichever party. Even if some branch of the government took on the task of preventing such corruption, it's not so clear what kind of rule could work against it effectively. I would like to propose a rule here that could work.

The basic trick used in gerrymandering is to concentrate the voters of the minority party. The voters of the majority party are spread across districts, so there are just enough to win in a very large number of districts.

So here is an effective anti-gerrymandering rule: for each x, there cannot be more districts with more than (50+x)% minority party voters than there are districts with more than (50+x)% majority party voters.

In other words, minority party voters cannot be concentrated in districts more than majority party voters are.

This is a simple rule that would prevent the worst abuses of gerrymandering.