[EL] Milhiser article on partisan gerrymandering

Thu Dec 4 08:38:18 PST 2014

In addition to the deficiencies of most automated algorithms failing to adhere to all legal requirements like the VRA, systems science research indicates that given current computing limits we cannot be sure plans produced by automated algorithms are indeed random. Thus, we cannot apply statistical tests. Furthermore, as defense lawyers vividly demonstrated in the recent Florida litigation by displaying a series of maps to impeach Rodden’s testimony, Chen and Rodden’s algorithm does not necessarily produce compact districts. This evidence was so damning that plaintiffs dropped Rodden’s testimony and expert report from their arguments. Which is to say, there are theoretical and implementation assumptions that underlie automated algorithms that go underappreciated by their proponents, which can lead to consequences when a bright light is shined upon them by opposing experts. (Ironically, defendant’s expert for Republicans in Florida was Nolan McCarty, the journal editor who published Chen and Rodden’s QJPS article that found Republicans didn’t gerrymander, which contrasted with the expert report for plaintiffs.)

For these reasons, Micah Altman (if I may speak for him) and I believe that while automated algorithms can illuminate alternative plans -- an idea first proposed by Nagel in 1965 -- human beings approach redistricting in fundamentally different ways that can explore a greater range of legal plans than what computers are capable of producing. For example, during Mexico’s recent redistricting humans repeatedly beat an optimization algorithm using simulated annealing (from a paper still in working form, but willing to share on request). Because these human-generated plans still cannot guarantee to randomly sample from the feasible set of redistricting plans, we cannot apply statistical tests to them. However, by the weak axiom of revealed preferences, human and computer-generated plans can reveal preferences of a redistricting authority, in that if a plan exists that beats an adopted plan on all metrics that the redistricting authority stated it cared about, and it differs on another criteria, say is more “fair”, then we can infer that the redistricting authority didn’t prioritize fairness. This approach is routinely used by the courts when they ask plaintiffs to produce a plan to correct alleged constitutional defects. This idea, in part, motivated our creation of open-source redistricting software called DistrictBuilder (www.districtbuilder.org <http://www.districtbuilder.org> ), which supported public mapping advocacy efforts across the United States and was used by a few redistricting authorities, too.

Some papers on our approach of crowd-sourcing redistricting, and what these plans reveal about the preferences of redistricting authorities:

Public Participation GIS: The Case of Redistricting

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2321870

The Promise and Perils of Computers in Redistricting 

http://informatics.mit.edu/publications/promise-and-perils-computers-redistricting

Paradoxes of Political Reform: Congressional Redistricting In Florida

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2421908

Redistricting by Formula: An Ohio Reform Experiment

http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2450645

A Half-Century of Virginia Redistricting Battles: Shifting from Rural Malapportionment to Voting Rights to Public Participation 

http://informatics.mit.edu/publications/half-century-virginia-redistricting-battles-shifting-rural-malapportionment-voti-0

============
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From: law-election-bounces at department-lists.uci.edu [mailto:law-election-bounces at department-lists.uci.edu] On Behalf Of Nicholas Stephanopoulos
Sent: Wednesday, December 03, 2014 11:08 AM
To: Rob Richie
Cc: law-election at UCI.EDU
Subject: Re: [EL] Milhiser article on partisan gerrymandering

More comprehensive versions of the Duke study have been carried out by Jowei Chen and Jonathan Rodden (see here <http://www-personal.umich.edu/~jowei/florida.pdf> ) and Roland Fryer and Richard Holden (see here <http://www.stat.columbia.edu/~gelman/stuff_for_blog/fryer.pdf> ). None of these studies takes the VRA into account (or, for that matter, other common criteria such as respect for political subdivisions and respect for communities of interest). So I think it's fair to say that we don't know what the partisan implications of randomly drawn lawful plans would be. We know what the partisan implications are of randomly drawn and maximally compact plans, but these aren't the same thing as legally valid plans.
On the issue of gerrymandering more generally, Eric McGhee and I have a forthcoming article (see here <http://papers.ssrn.com/sol3/papers.cfm?abstract_id=2457468> ) in which we introduce a new measure of partisan distortion and argue that it could serve as the basis for a legal test. We're responding not to Vieth but rather to the favorable comments by five Justices in LULAC about the concept of partisan symmetry.

Nick

On Wed, Dec 3, 2014 at 5:30 AM, Rob Richie <rr at fairvote.org <mailto:rr at fairvote.org> > wrote:

The mathematicians' failure to acknowledge the Voting  Rights Act is just  one indicator of how  such simulations are only  as good as the assumptions that govern them. Worth doing and discussing, but not to be accepted without an understanding of the impact of those assumptions.

Anther example in the article is that it is based on analyzing the actual votes cast in House races rather than the more indicative relative presidential vote. The 2012 elections included some over-performing Democratic candidates including one incumbent who received more than 20% of votes from backers of Mitt Romney -- an extraordinarily high crossover vote in today's partisan climate that didn't continue this year.

I'll also address one lurking  part of this discussion: the myth that section two of the Voting Rights Act is the cause of the Democrats' problems in the South. That certainly was true in the past,  but it is not today absent adoption of independent redistricting commissions. That is, the need to create majority-minority districts is the only reason that Republicans drew plans that allows Democrats to win any congressional seats at all in Alabama, Louisiana, Mississippi and South Carolina. Republican mapmakers also could have knocked Democratic representation down two seats in Georgia and one seat each in North Carolina and Tennessee. (We show this in some alternative southern congressional districts <http://www.fairvote.org/assets/Uploads/Redistricting-Reform-in-the-South.pdf>  map work we did earlier in the year.) 

As it is, the combination of single winner districts, polarized voting and partisan  control of redistricting makes most of the South a true basketcase when it comet representative democracy in congressional elections. Note that when we issued our final November 2016 election projections <http://www.fairvote.org/research-and-analysis/congressional-elections/fairvotes-projections-for-u-s-house-elections-in-2016/>  earlier this month (on November 6th, more than two years before the 2016 elections), we projected winners in more than 85% of districts using a methodology that resulted in a single error in more than 700 projections in 2012-2014. 

In the South, the numbers are  extraordinary -- setting aside Florida and Virginia, there are 126 districts in the remaining southern states and the border  states of Kansas, Missouri, Kentucky and West Virginia. We project winners in 125 of them; if all these seats were open, we'd still project 123 of them. The prospects of redistricting reform in any of these states is very slight without Congress asserting its power over the time, place and manner of elections -- something it onl  is using right now involving redistricting  to mandate gerrymandering (that is, mandate single-winner districts, as it required in 1967).

Rob Richie

On Wed, Dec 3, 2014 at 1:29 AM, Douglas Johnson <djohnson at ndcresearch.com <mailto:djohnson at ndcresearch.com> > wrote:
Such studies have been done for decades. In fact the difference between the party getting more votes and the party getting more seats was fairly central to many of the arguments (though not to the ruling) in the Tom Delay Texas re-redistricting case. There is no “genius” to such analysis, despite Millhiser’s use of that term. 

The more simplistic versions of such studies (including this Mattingly and Vaughn study) completely ignore the requirements of the Voting Rights Act. In fact, the phrase “voting rights act” never even appears in the Mattingly and Vaughn paper. The only remote reference to it is “The two districts with largest African American representation had on average around 36% and 32% African American population, which compares favorably to the state wide percentage of 22%, but not to the current districts.” That sounds to me either like a total failure to understand the VRA, or a knowing attempt to distract reporters from recognizing that they’re deliberately ignoring the VRA despite the VRA’s significant impact on the redistricting plan in question.

Millhiser specifically condemns redistricting plans that “are almost certainly the product of a legislature that carefully designed the maps to produce a desired result.” But that is exactly what the VRA requires – on a racial/ethnic and language front. The difficulty is not in proving that redistricting plans are not random (or at least that they’re not the most-compact plan possible). The difficulty is in proving the plans are drawn for partisan purpose, as opposed to drawn ensure compliance with the VRA or to follow city, county, or other community of interest boundaries. The filings in Vieth  provide a look at a variety of potential tools for such analysis. Millhiser and Vaughn do not. 

This is a topic in desperate need of good solid analysis and study. I often describe Vieth as the Supreme Court’s version of a “Call for Papers.” Unfortunately neither the article nor the study qualify as such.

-          Doug

Douglas Johnson, Fellow
Rose Institute of State and Local Government
at Claremont McKenna College 
 <mailto:douglas.johnson at cmc.edu> douglas.johnson at cmc.edu
 <tel:310-200-2058> 310-200-2058 

 <http://electionlawblog.org/?p=68747> “If The Supreme Court Reads This Study, It Could End Partisan Gerrymandering Forever”

Posted on  <http://electionlawblog.org/?p=68747> December 2, 2014 8:10 am by  <http://electionlawblog.org/?author=3> Rick Hasen
 <http://thinkprogress.org/justice/2014/12/01/3597643/this-study-could-end-the-worst-kinds-of-gerrymandering-if-the-supreme-court-took-the-time-to-read-it/> Ian Millhiser writes.
I was surprised to see no mention of Voting Rights Act requirements in drawing these districts. 

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