Monday, October 17, 2005

Visualizing Schwarzenegger's redistricting scheme:

Recently, there has been some detailed analysis of California's proposition 77, supported by Schwarzenegger, which takes congressional redistricting out of the hands of the Democratic-controlled legislature (see Ezra Klein, Brad Plummer, Matt Singer, Mark Kleiman). If the proposition passes, districts would have their boundaries set by a panel of judges. This is a typical good-government initiative that sounds reasonable.

Unfortunately, if a blue state like California does it while states like Texas and Florida continue with their red-friendly gerrymandered districts, at the national level the Democrats would suffer.

But let's set that aside for the moment. The proposition as it now stands has a bias in favor of Republicans. That's because the judges aren't completely free to set boundaries. There are guidelines that mandate "compactness," such as maximizing the number of whole cities in each district, and minimizing the number of multi-district cities.

Since Democrats tend to be concentrated in cities, this means compact districts will have a very high proportion of Democrats, leaving more slightly-Republican-favored districts in the suburbs and rural areas. It's a classic gerrymander hiding inside the compactness formula.

The mathematics for this can be complex, depending on non-linear curves plotting the ratio of Democrats to Republicans as one moves from population centers, and also on what's know in statistics as "bin size". But you can still get a sense of how it works with a simple graphical representation of how a neutral state (50/50) can, under a proposition like California's 77, end up with congressional districts that favor Republicans.

Start with a population of 24: 12 blues, 12 reds.
Congressional seats: 4
A city (at the left) which is 100% blue, and suburban/rural areas with a red:blue distribution of 2:1

In a fair (re)districting, one that has the congressional representation mirror the population's political orientation, we would have two blue seats and two red seats. A districting plan that would attain that goal might look something like this: (note the city at the left has multi-districts)

But if the priority is to create compact districts, along with the avoidance of multi-district cities, you could end up with a redistricting like this:

Instead of two blue and two red seats, we now have one (very solid) blue seat, and three red seats. So while Schwarzenegger's plan sounds reasonable, the devil is in the details, and it turns out to be not so fair after all.

UPDATE: It's possible that other guidelines in the proposition will work to the Democrats advantage, but on the whole, Republicans are the likely gainers. In any event, it doesn't seem to do much for competitiveness. And anyway, the fact that Schwarzenegger is beating the drum for it gives us pause. Since becoming governor, one of his top priorities has been to enfeeble the Democrats (e.g. through other initiatives like Proposition 75).


It's a very elegant explication. However, a much simpler reason to refuse it is far more elegant: a REPUBLICAN is pushing the scheme, and therefore its purpose can only be evil. Show me any example in the last 14 years that a Republican advanced any legal or legislative initiative that favored anyone other than the Republican Party and its paymasters.


By Anonymous Anonymous, at 10/17/2005 8:25 PM  

I wish you would stop using reason without a license. Things would be much less contentious if you would just agree with the movie star.

By Blogger brainhell, at 10/17/2005 8:49 PM  

I think the Arnold-wants-it-so-it's-wrong stance is stupid, but you address an important point about prop 77 in discussing binning etc. So I'd like to know why no expert with the requisite software has chimed in about the relative competitiveness of the current and proposed districting and the ratio of n_dem/n_rep(voters) to n_d/n_r(congresscritters) in the two cases. I think the fact that Pelosi hasn't said that we'll lose a bunch of seats argues for little overall effect on the above ratio and perhaps some positive effect on competitiveness.

By Blogger rilkefan, at 10/17/2005 11:35 PM  

Well, this is no time to give the Republicans an inch. So I'll vote no.

But somewhere down the line I'd like to see redistricting along the lines of this Prop. Why?

Because districts should reflect "real" natural boundaries-- areas populated by liberal people should be able to choose between liberal politicians, and not be in convoluted districts that force them to go to battle with a roughly equal number of conservatives in every election.

If there were some VERY blue districts, that might allow some folks from the democratic wing of the Democratic party to get elected, get seniority, get influence in Congress, and be a national voice for democratic values.

By Blogger Clark, at 10/18/2005 9:12 AM  

Clark, if most of the Democrats are clumped into 80% Democratic districts, while the majority of the districts are 55% Republican, then the Democrats will never regain the majority in the House. Where exactly would the influence in Congress you're hoping for come from?

By Anonymous Anonymous, at 10/18/2005 9:30 AM  

rilkefan wrote, I think the Arnold-wants-it-so-it's-wrong stance is stupid...

Why? It certainly can't be the end-of-the-line as far as reasoning goes, but it's an important clue, or signal.

clark wrote, Because districts should reflect "real" natural boundaries-- areas populated by liberal people should be able to choose between liberal politicians, and not be in convoluted districts that force them to go to battle with a roughly equal number of conservatives in every election.

But if you don't do this right, it could lead to a lopsided number of right-wingers in Congress.

Clearly the right way to do things is to have proportional representation at the state level, i.e., the Representatives are for the entire state, not a given district, with voting done via some scheme that's reasonable, maybe instant runoff or whatever.

The notion that every district should have "their own" rep is just stupid.

By Anonymous Anonymous, at 10/18/2005 9:32 AM  

"Clearly the right way to do things is to have proportional representation at the state level..."

Agreed. But I've never heard anyone but Greens talking about this option.

To kcindc: good point. But the solution to the Rep majority isn't to gerrymander with the intent of creating districts that are "balanced" between Dems and Reps, because that way left leaning areas can never get left leaning pols elected. As things stand there are lots of rabidly right wing folks in Congress, but nobody leftie enough to say out loud "Universal Health Care," "Bring the troops home," or "Tax the rich."

Perhaps liberals have just got to take the long-term view, and try to outbreed the conservatives. (Just kidding.)

By Blogger Clark, at 10/18/2005 12:19 PM  

I didn't say anything about creating districts that are balanced between Democrats and Republicans, at least at the level of the individual district. Clearly that would be insane, because a state that was 51% Republican would end up with N districts that were all 51% Republican and thus could end up with an all-Republican congressional delegation.

I think the object should be to have the representatives reflect the distribution of views within the state as a whole. That might require proportional representation, as Anonymous says. That does have the drawback of not letting people have "their own" congressperson to write to, but I'm not convinced that's meaningful for much other than venting anyway.

By Anonymous Anonymous, at 10/18/2005 4:53 PM  

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