Mr. Illini's Chicagoland Township Map Thread

[jimrtex]

And of course, I couldn't not do an annotated version.

Why are Zion, Pembrooke, and Waukegan so heavily minority?

I did a look-up on Pembroke, and it has the worst soil in eastern Illinois, and was available to black farmers.  One anecdote said that there were more PhD theses written on the area than any other subject.

Zion was founded as a religious utopian town (they banned not only the usual vices, but tan-colored shoes).  The founding sect adhered to a flat earth doctrine into the 1930s.   I didn't find an explanation for the population, other than there were two nuclear plants.

[jimrtex]

I had posted this earlier, but it is relevant to Chicagoland.



The concept of Cumulative Vote Share is that as you add in precincts, one-by-one, you can calculate the share of the vote at that point in the count. This is quite familiar from election night. The order the votes are accumulated can be significant. In Pennsylvania, the votes from Philadelphia are reported first, and the initial vote share is extremely Democratic, the rest of the night the Republican share will climb.

Imagine that all precincts used paper ballots, and the election clerks in each precinct were equally efficient, such that the could count one ballot in some period of time. Let's assume 6 seconds per ballot, or 10 ballots per minute, then if there were 405 ballots cast, it would take 40m30s to count the ballots, at which time they would call the results in. A precinct with 505 ballots cast would take 10 minutes later to count.

At the county board of elections, the precinct results would be added in and the cumulative vote share reported. This is the blue line in the chart. So it might be reported that with 20% of the vote counted, Rauner has 38.7%.

Conspiracy theorists believe the fact that Republican CVS climbs as larger precincts are added in proves vote fraud since it is "common knowledge" that larger precincts are in Democratic-leaning cities. This is not true. For example, the largest Cook County precinct is in Hanover, which is as far as you can get from Chicago and not be Kane County.

They also overlook that turnout in most elections, and particularly non-presidential elections are in lower economic status areas, which typically are more Democratic. With fewer votes cast, they could be counted sooner, and added into the cumulative vote share. Places like Evanston and Oak Park have relatively high turnout, and are strongly Democratic, so the turnout differential is not strictly speaking partisan. But turnout in Cicero was horrible, and it was very Democratic.

But imagine that the county board of elections called the precincts. They might assume uniform turnout, and call the precincts in order of registered voters. With fewer voters, there will be less votes to count, so they will likely be done by the time the call is made. If precincts are ordered by number of registered voters, the red curve results.

It is quite level, with just a minute Republican trend in larger precincts. There may be a delay in adjusting precincts. If an area is declining in population, there may be resistance to closing familiar polling places. If an area is increasing in population, or at least remaining steady, they may not want to create additional polling places. Areas that have lower turnout, are also likely to have lower registration.



This chart shows the relationship between Rauner%, and Turnout%. The bubbles are colored based on Rauner%, and bubble size is based on registration.

It may be easier to see this chart directly in the spreadsheet.

Cook County Rauner 2014

There is a bit of optical illusion. The countywide turnout was 48.5%, and Proviso and Worth are just below that, with Thornton, Bloom, Bremen, and Niles a couple of points lower. There is a lot of overlap in the blue cluster around 60% Rauner (Ormond is hidden behind Palatine, for example), such that some of the lower turnout areas such as Schaumberg may have more visual weight, with their turnout perceived as being at the lower end of the circle, rather than as its center.

Overall, the more Republican townships have a bit higher turnout than most of the more Democratic townships, and there are some very low performing Democratic areas. I would interpret the turnout in Rich, Thornton, and Proviso as indicating that black turnout is less tied to economic status than that for white and Hispanic voters.

[jimrtex]

Is the high turnout Quinn township to the upper left of Riverside representing River Forest?

Yes. I used the Rauner percentage of the total vote, rather than the two-way vote, so it was not a tie, and the pink color covered 40% to 49.99...%. Rauner also had a plurality in Leyden.

Countywide, the Libertarian Chad Grim had 1.9% of the vote.

[jimrtex]

This chart illustrates the effect of differential turnout.



Countywide turnout was 48.5%. The calculation assumes that if turnout in a township had been average, but the margin the same, what would have been the result.

For example, in Cicero it was Quinn 6540:Rauner 2154, a 4386 margin for Quinn. Rauner had 24.8% of the 2-way vote. There were 8664 Rauner+Quinn voters. Turnout was 30.8%.

If Cicero had had 48.5% turnout, then there would have been 13,608 Rauner+Quinn voters. Had the margin been the same (4386), then Rauner would have received 33.9% of the two-way vote.

That is, the effect of the low turnout in Cicero was the same as if Rauner had +9.1% more support than he actually did. Democrats not voting, is just as good for Republican outcomes, as Republicans voting.

A contrary example, in Oak Park it was Quinn 15062:Rauner 4905, a 10,157 margin for Quinn. Rauner had 24.6% of the 2-way vote, almost identical to Cicero. There were 19,967 Rauner+Quinn voters. Turnout was 58.3%, almost 10% higher than the countywide average.

Had Oak Park had 48.5% turnout, then there would 16,500 Rauner+Quinn voters. Had the margin been the same (10,157), then Rauner would have received 19.2% of the 2-way vote.

That is, the effect of the high turnout in Oak Park was the same as if Rauner had -5.3% less support than he actually did. Democrats voting, is just as bad for Republican outcomes, as Republicans not voting.

The largest effect is for areas that had relatively one-sided outcomes AND had relatively high or low turnouts. It didn't matter that River Forest had high turnout, since the result was tied.

[jimrtex]

Do you know where I could get a statewide map?

Of what exactly - townships, precincts, counties, localities, etc?

Townships and/or precincts.

The IL State Board of Elections collects pdfs of precinct maps from each county. Usually it's by township. Some cities have independent election commissions so they are separate from the county. The collection can be found at

http://precinctmaps.elections.il.gov/

How close would the 2010 census VTD's be?

[jimrtex]

Do you know where I could get a statewide map?

Of what exactly - townships, precincts, counties, localities, etc?

Townships and/or precincts.

The IL State Board of Elections collects pdfs of precinct maps from each county. Usually it's by township. Some cities have independent election commissions so they are separate from the county. The collection can be found at

http://precinctmaps.elections.il.gov/

How close would the 2010 census VTD's be?

The law requiring election authorities to report their precinct boundaries went into effect early this year. The goal is to have the precinct maps in advance of each election, but there is no requirement to report historical boundaries. Most counties will have submitted boundaries used for the 2014 election, and most of those would have last been adjusted in 2011 after the 2010 remap.  Some made no changes at all and they will match precincts from the 2000's including those on DRA. A few, including DuPage, made major changes this year in advance of the 2016 elections, so they will be no help for 2012 or 2014.

Are those DuPage changes in selected townships?

In Massachusetts, the towns and cities are required to submit shapefiles to the SOS. Of the towns that I found precinct maps for, they were produced by the SOS. I suspect that in Massachusetts the precinct maps including shapefiles could be obtained from the SOS.

Looking at a sample of maps in Illinois shows that they were produced by the respective BOE. Adams looks like they were produced on top of census maps. Clark County used their GIS system. Woodford might not have just used a state highway map - unless precincts are coincident with townships.