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(50,049 posts)
Mon Apr 18, 2016, 02:05 PM Apr 2016

The Most Exciting Attack On Partisan Gerrymandering In Over A Decade


The “Efficiency Gap”

Stephanopoulos and McGhee’s central insight is that gerrymanders operate by forcing the disadvantaged party to “waste” votes. Some voters are shunted into districts where their party’s candidate has no chance of winning, a process known as “cracking.” Others are crammed into districts that so overwhelmingly favor their party’s candidate that casting an additional ballot for that candidate merely adds padding to a foregone conclusion, a process known as “packing.” “A gerrymander,” Stephanopoulos and McGhee write, “is simply a district plan that results in one party wasting many more votes than its adversary.”

To sniff out possibly gerrymanders, Stephanopoulos and McGhee begin by counting each party’s “wasted” votes. As the three-judge panel hearing the Whitford case explained in a recent opinion, a wasted vote occurs when a voter either casts a ballot “for a candidate who lost the election” (suggesting that the voter was targeted by cracking), or if they cast a ballot “for the winning candidate, but in excess of what the candidate needed to win” (suggesting that the voter was packed).

As Stephanopoulos and McGhee note, some number of wasted votes are inevitable in elections involving single-member districts. But a fair map should produce roughly equal numbers of wasted votes for both parties. To determine which maps diverge too far from the ideal, the two scholars offer a metric they call the “efficiency gap,” which is calculated by taking the difference of the two parties’ wasted votes and then dividing it by the total number of votes cast. The plaintiffs in Whitford (speaking through a team of lawyers that includes Stephanopoulos) offer an example of how to calculate this figure in their complaint:

Suppose, for example, that there are five districts in a plan with 100 voters each. Suppose also that Party A wins three of the districts by a margin of 60 votes to 40, and that Party B wins two of them by a margin of 80 votes to 20. Then Party A wastes 10 votes in each of the three districts it wins and 20 votes in each of the two districts it loses, adding up to 70 wasted votes. Likewise, Party B wastes 30 votes in each of the two districts it wins and 40 votes in each of the three districts it loses, adding up to 180 wasted votes. The difference between the parties’ respective wasted votes is 110, which, when divided by 500 total votes, yields an efficiency gap of 22% in favor of Party A.

An efficiency gap of more than 7 percent, these plaintiffs claim, is indicative of a partisan gerrymander. When combined with evidence that the state acted intentionally to give one party an advantage, they argue that courts should presume that a map that produces such a high efficiency gap is an unconstitutional partisan gerrymander.
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NV Whino

(20,886 posts)
1. That seems overly complicated
Mon Apr 18, 2016, 02:26 PM
Apr 2016

Generally, a simple look at a map will determine unconstitutional gerrymandering.

There are exceptions, and I suppose this formula would be necessary in that case, but generally, it's obvious.


(12,977 posts)
2. When you're trying to bring court cases, nothing is obvious
Mon Apr 18, 2016, 03:16 PM
Apr 2016

There are also relatively benign reasons for a modest amount of gerrymandering, such as lumping minority voters together in a single district to give them representation of their own. So it's only when the funny-looking districts overwhelmingly favor one party over the other that you can say the state as a whole has been gerrymandered.


(20,697 posts)
4. Not always. Some Gerrymandering doesn't "look" Gerrymandered.
Mon Apr 18, 2016, 03:43 PM
Apr 2016

Particularly where you're adding continguous areas in, to crack or pack a district.

For instance consider a state with one large urban area representing nearly half the state population, and the rest small cities, towns, and rural spaces, with a total of six CDs. The central urban area is deep blue, but it is surrounded by bright red suburbs. The northern end of the state with rural territory and a few small cities may be blue-with-purple bits, the south with a small city and lots of rural area deep red with a few purple bits in the city. Pre-gerrymandering, this state reliably sent three Democrats and two Republicans to Congress, and usually four Democrats and two Republicans. Occasionally one seat that represented northern rural areas plus the north outlying urban suburbs switched up to GOP, but usually the balance was 4/2 and 3 of the Dem seats were quite reliable.

Perfectly legitimate-appearing maps can be drawn, That would "crack" two of the dark blue mostly-urban districts by creating a packed "central" district conceded to the Dems, and pulling contiguous purply neighborhoods into line with those bright red burbs, putting one more into the GOP bag, tipping the balance on that switcheroo district to "reliable GOP" and leaving one more district up for grabs. Then you have your reliable GOP south district, your mostly-blue north end, and hey, presto! A perfectly reasonable map has changed the state balance to 3 GOP, 2 Dem and a switcheroo.

BUT with half the state's population in the bright blue Big City, this model would indicate exactly how those votes have been laid to waste.

I like it!



(1,178 posts)
7. My hometown was gerrymandered back in the 60s
Mon Apr 18, 2016, 04:03 PM
Apr 2016

I grew up on the South Shore of Long Island. We had a very progressive Congressman Allard Lowenstein from 1968-70.


The NY state legislature gerrymandered the district to remove a number of Democratic towns and to add a predominantly Republican town. As a result, we had more than 20 years of Republican representatives until the districts were eventually adjusted. The gerrymandered district didn't look particularly unusual. However, if you dig deeper, you would find that there was a religious minority component to the redistricting, similar to the tactics Republicans are using today with racial minorities. Several heavily Jewish towns (Democratic) were removed and a Catholic town (Republican) was added to dilute the Jewish vote. I'm glad someone is now using some more sophisticated analysis to identify the more insidious examples of gerrymandering!



(7,321 posts)
10. Seems to describe California.. at a glance. But I'm not a student on the analytics.
Tue Apr 19, 2016, 01:20 PM
Apr 2016

just have a pedestrian understanding of it.

The op seems a bit complicated to wrap my head around in terms of the "wasted" votes, (what does that actually mean, disenfranchisement? ) but I also understand it's legalese for court purposes.


(10,794 posts)
8. Complicated, perhaps, but measurable and unbiased.
Mon Apr 18, 2016, 04:46 PM
Apr 2016

The formulas that the scholars present can actually be used to determine gerrymandering without resorting to "expert" opinions or other soft and biased methods.

If you want to prove gerrymandering, then simply add up the votes and do the math. No opinions required. This can be enacted as legislation or a court can order it.

Of course, the formula isn't foolproof. It assumes that voters always vote for one party or another. If there is a big swing in popular sentiment, and people switch parties, it may break the algorithm.


(1,769 posts)
9. Courts cant base on Subjective guesses
Tue Apr 19, 2016, 11:42 AM
Apr 2016

Courts need to base decisions on facts. And a fact is; Something that can be measured. So of course they need to have these formula's if they expect to win.

Even if outside is a frozen wasteland, a statement like, "It is cold outside" is only an opinion. If one were to say, "It is -25 degrees outside," then that is based on a measurement and can be considered a fact (if it is correct).

So a court needs to have facts to consider or the case will just get thrown out.

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