VA – A foreigner’s (first) attempt at a “good governance” redistricting map for Virginia

Dear all,

This is the first time I've tried using Dave's App and making a redistricting map. I'm hoping you could tell me what things I've done wrong. (For one, I've kept the population of each district very close to the target population, 3,000 off at most, because I didn't know just how close you have to keep it. Could I have been more flexible?)

This is the map, but please do read on:


First off, I had an idea with this map. Most of the redistricting maps here are drawn, with great expertise, to either create the most realistically (or unrealistically) Democratic-friendly map; or, in a know-your-enemy / worst-case-scenario kind of way, the most GOP-friendly map; or the map that best fits the current political realities of the state, trying to guess what the real map will end up being.

Since I have nowhere near enough expertise to weigh in, I've just been observing, with some awe. But, as a foreigner, I still have trouble getting over my initial incredulity at the whole American practice of gerrymandering in the first place. The kind of gerrymandering that yields these sometimes mindbogglingly contorted looking districts, tracing unlikely looking paths from, say, the suburbs of one city to those of another halfway across the state, often seemingly without regard to keeping communities together. It's one of the oddest and unhealthy looking aspects of the US political system, for an outsider.

I'm from a country where we don't have any districts at all (it's all PR), and both in my adopted home country and the big European countries I know best (Germany, the UK), nothing like this kind of gerrymandering seems to exist. And often when I see the draft maps here, I can't help fantasizing about what a redistricting map purely based on good governance would look like. (I'm really curious what the new CA and FL maps will look like!)

Continued beneath the fold … 

That said, among the many things I have learned about on SSP is the VRA, and I approve. I don't like the 60+% black/hispanic vote sinks that segregate the minority altogether and allow the VRA district incumbent practically guaranteed re-election. But I have totally embraced the need for districts in which minority group candidates are favoured, so minority groups are represented more proportionally in Congress. It's history's bill: it would be great if a black candidate stood as good a chance to be elected anywhere, but the reality is that in too many parts of the country, black/hispanic candidates will only be elected in black/hispanic-majority districts.

I wanted to draw my ideal "good governance" map for a state, the way it would look if there were no bothersome laws, legislative majorities or incumbencies to take account of.

I drew up these criteria:

  1. The number of districts that lean one way or another politically should be roughly proportionate to the parties' general share of the vote. (E.g.: don't stack all the voters of one party into two districts so the other party can easily win in five, when the two parties get about equal amounts of votes altogether).
  2. There should be a number of districts where a minority group candidate would be favoured roughly proportional to the group's share of the overall voting age population. However, districts in which a minority group makes up a small majority (<55%) or a mere plurality, and "coalition" districts in which minorities together outnumber whites should be preferred over segregating individual minorities in 60%+ vote sink districts.
  3. There should be as many competitive districts as possible, both to avoid safe incumbents coasting to victory without having to worry about accountability; and to keep the number of those whose vote doesn't "count" because their party is irrevocably in opposition to a minimum.
  4. Districts should be compact and keep communities of interest together.
  5. While uniting communities of interest is good, it is not beneficial for public policy if the residents of cities and surrounding suburbs are pitted against each other. (A story that struck me was the fight, at a state level I imagine, over public transport in Atlanta, in which the residents of the suburbs managed to block the extension of the city's public transport system because they feared that it would just bring more blacks into their neighbourhoods.) The map should draw cities and surrounding suburbs into common districts where possible.

As you will recognize, but I didn't quite realize beforehand, some of these points make some of the others impossible. Applying point 2 in particular throws a spanner in the works when it comes to points 4 and 5. Creating that many minority-majority districts means contorted shapes, and splitting off black or hispanic city neighbourhoods. Since minority voters tend to vote Democratic, creating more minority districts also means creating more safe Democratic districts, so it's a problem with point 3 too.

Virginia turns out to neatly illustrate all this. My other problem is that I know little about Virginia, so it's hard for me to guess where communities of interest lie exactly in any case. (Any feedback much appreciated.)

Virginia redistricting - data table

(All these data from within Dave's app. I noticed that if you download the data on race by congressional district (18+ population, hispanic and non-hispanic by race) from the census site, there's slight variations, though never more than 1% up or down.

Here's maps with some more detail:

Redistricting map NoVa

Redistricting map Richmond 

Redistricting map Hampton Roads 

How does this stack up with my criteria?

  1. Fulfilled: My redistricting map creates six Republican districts, four Democratic districts, and one Democratic-leaning district.
  2. Fulfilled: The map creates two districts in which a minority group has a plurality (blacks in VA-3 and VA-4) and a third district in which the minority groups together outnumber non-hispanic whites (VA-11). (I tried to group together disproportionally hispanic towns and neighbourhoods in VA-11, so there’s at least one district where they make up as much as 23% of the VAP – as close to having a district of their own as possible.) That's three minority-favoured districts compared to one now. Pitfall: while non-hispanic whites make up no more than 45% of each of these districts' VAP, they are 43%-45% in each, meaning that disparate turnout rates could also end you up with no minority Congressmen at all. Unlikely in an Obama year, but a concern otherwise.
  3. Failed: My redistricting map actually makes most districts less competitive. This is due to applying point 2. In order to create two more minority-favoured districts, I had to take black votes out of largely white districts, shoring up Republican majorities there. I also took some from the existing minority-majority VA-03, a Democratic vote sink – but that means that instead of having one D+38 district in the south, I ended up with two, still safe D+17-23 districts. Same in the north – by taking black and hispanic precincts from VA-8, I reduced that Democratic vote sink from D+32 to a still safe D+19, while creating an additional safe Democratic seat in VA-11 (D+18). All in all, I went from four arguably toss-up seats (VA-2, VA-4, VA-5 and VA-10) to one (VA-10).
  4. Partial: In the Northeast and the Southeast, districts are pretty contorted looking because of heeding point 2 (though I did manage to cut VA-03 short of stretching all the way up into Richmond neighbourhoods). Elsewhere, some districts are reasonable compact (VA-05 and VA-09, as well as VA-10 up north), but VA-1 stretches a long way across the state… How could this be done better, and do these districts unwittingly split any communities of interest?
  5. Partial: Creating three minority-favoured districts meant splitting a number of cities, in particular Richmond, but also Norfolk, Hopewell, Danville and Franklin – plus the agglomeration in NoVa.

Here's maps of each individual district:


Redistricting map: VA-01


Redistricting map VA-02


VA-03 redistricted 

VA-04 (or as I like to call it, the dragonboat

VA-04 redistricted 


VA-05 redistricted 


VA-06 redistricted

VA-07 (the crab, or is it a lobster?)

 VA-07 redistricted


 VA-08 redistricted


 VA-09 redistricted


 VA-10 redistricted


VA-11 redistricted

Analyzing Obama’s Weak Spots – Part 1

This is the first part of three posts analyzing the congressional districts President Barack Obama underperformed in.

Congressional Districts

By most accounts, Senator Barack Obama dominated the 2008 presidential  election. He won an electoral landslide, winning Republican-leaning states such as Indiana and North Carolina which his campaign targeted. Compared to 2004, the nation shifted almost ten points more Democratic.

Mr. Obama improved from Senator John Kerry’s performance almost everywhere. More than 90% of congressional districts voted more Democratic than in 2004. Yet this means that at least several dozen congressional districts were more friendly to Mr. Kerry than the Illinois Senator. I have mapped these districts below:

Analyzing Obama's Weak Spots

More below.

(Click here for a much better view of the map).

There is a clear pattern here: Republican-shifting congressional districts are found along a diagonal line stretching from Louisiana and Oklahoma to southeastern Pennsylvania, roughly along the Appalachian mountains. This is not exactly startling news; ever since the primaries, Mr. Obama’s weakness in these regions has been well-noted. The five states that shifted Republican from 2004 – Arkansas, Louisiana, Oklahoma, Tennessee, and West Virginia – are all located here.

The exceptions to this pattern, however, constitute items of considerable interest. Some of these have fairly simple explanations. Arizona’s 1st district voted more Republican, for instance, mainly because Arizona was Senator John McCain’s home state.

Other districts, however, go against commonly-held political wisdom. Take LA-2: a black-majority, inner-city district located in New Orleans (represented, ironically, by Republican congressman Joseph Cao). While LA-2 strongly supported Mr. Obama, black depopulation in the aftermath of Katrina made this support less than that in 2004.

Another example can be found in the northeast:

Analyzing Obama's Weak Spots - Part 1

Republicans do better in five Massachusetts districts and one New York district.

This movement stands in contrast to the narrative of Democratic dominance in the northeast. Most in the beltway have ignored this trend, or dismissed it as simply the loss of Mr. Kerry’s home-state advantage. Whether this is true or not, there is quite a lot of interesting stuff to be said on these districts. The next post will be devoted solely to exploring this pattern.


MI-2: Riemersma (R) Officially In

No surprise given the chatter, but the GR Press has coverage of the official announcement this morning:

Eleven months from the 2nd district GOP congressional primary, the race is shaping up as a battle of the insiders vs. the outsider with a familiar name.

Former NFL star Jay Riemersma kicks off his formal campaign today with a speech in Holland. He vows a new brand of politics for the conservative district that U.S. Rep. Pete Hoekstra, R-Holland, has held since 1993. Hoekstra is running for governor.

“The last thing we need right now is legislative experience,” said Riemersma, 36. “What we need is leadership, strong conservative leadership.”

Read the whole story here:…

The article is pretty positive towards Riemersma, allowing him to polish quotes bashing the other official GOP candidate Bill Huizenga (State Senator Wayne Kuipers is also expected to run). Riemersma raised $154,244 in the 2nd quarter filing report, of which $100,000 was his own money, compared to $76,201 for Huizenga. Riemersma touts his conservative creed by noting his connections to Focus on the Family, something which might appeal to the hard-core right in the 2nd District.

I’m still waiting on whether Kuipers runs; if he does, that makes this race a Ottawa County battle (three candidates) and provides an opening for a candidate from another portion of the district. Also, the 3rd quarter filing statement (due September 30) will also show how the two declared candidates are faring with raising funds for a sure to be expensive primary.

Just what is the Partisan Voter Index (PVI)?

Cross-posted at Election Inspection 

One of the things which I think tends to cause a little bit of confusion with regards to House races is the idea of Charlie Cook's Partisan Voter Index, so to solve a bit of the confusion, I'd like to take the time to discuss what the PVI is, how it's used, and its strengths and weaknesses. Just so we're clear, I have absolutely no connection to Charlie Cook or Polidata, nor should this necessarily be taken as their words. This is, essentially, a way to understand, at least to my mind, the logic behind the PVI.

So follow me, fellow SSPers and discover the wonder that is the PVI!

1. “What is the PVI?”

Wikipedia's entry defines it as:

The index for each congressional district is derived by averaging its results from the prior two presidential elections and comparing them to national results. The index indicates which party's candidate was more successful in that district, as well as the number of percentage points by which its results exceeded the national average. The index is formatted as a letter + number; in a district whose CPVI score is R+2, recent Republican presidential candidates received 2 percentage points more votes than the national average. Likewise, a CPVI score of D+3 shows the Democrats received 3 percentage points more votes than the national average.

Essentially, what the PVI attempts to do is to determine just how Democratic or Republican a district is compared to the rest of the country, which helps to give a better idea where the most and least competitive districts are.

2. “So does that mean that PVIs can change over time?”

Yes, every presidential election, the PVI is recalculated in order to determine what the voting patterns in each district were like. While PVIs are typically used with congressional districts, since we don't have the new data for the 2008 elections at the CD level yet, we'll use two different states as an example (Illinois, Indiana). First of all, let's figure out what the PVI of both states were before the 2008 presidential election: (Illinois 2000 and 2004 data; Indiana 2000 and 2004 data) First of all, we know that in 2000 and 2004 George Bush won 48% and 51% of the vote respectively (averaged out, the Republican nominee's vote percentage is 49.5) while the Democratic nominees Al Gore and John Kerry both got 48% of the vote. Using Illinois first, since we know that both Kerry and Gore got 55% of the vote in the state, we can determine that Illinois's previous PVI is 55-48, which gives us a PVI of D+7 (meaning that Illinois voted 7 points more Democratic than the rest of the country over the 2000 and 2004 presidential elections). For Indiana, we know that George Bush won 57% and 60% of the vote respectively (for an average of 58.5%), subtracting George Bush's national average from this state average (58.5-49.5) we find that Indiana has a PVI of R+9 (meaning that Indiana voted 9 points more Republican than the rest of the country). Now, to recalculate this for 2008, we take out the 2000 numbers of Al Gore and George Bush's first run and we add in Barack Obama and John McCain's numbers (for the national numbers, the average changes to 50.5% Democratic to 48.5% Republican) we would also take the new averages for Illinois (adding Obama's 62% to Kerry's 55% and dividing by 2 gives us 58.5%) and Indiana (adding McCain's 49% to Bush 2004's 60% and dividing by 2 gives us an average of 54.5%). Using the equations from above, we find that Illinois's PVI is now D+8.5 (which means that it moved more Democratic relative to the country) while Indiana's PVI changed to R+4 (meaning that it is now voting quite a bit less Republican than the rest of the country).

3. “Wait a minute, even though Obama won Indiana, its PVI is still so slanted towards the Republicans?”

Yes indeed. To make this a little easier, remember that the United States itself has a constant PVI of 0 (because it is being compared to itself). Because of this, it is possible for Obama to actually win a district that Kerry lost and yet the state gets a more Republican PVI. Looking at Florida (2000 and 2004) we can see that George Bush got 48% and 52% in 2000 and 2004 (with an average score of 50%), which makes Florida's old PVI R+0.5. In 2008, John McCain got 49% of the vote in Florida, so adding Bush 2004 and McCain's performance and averaging them gives the state an average Republican vote of 50.5%, which, in the context of the 2004-2008 national Republican average of 48.5, we can determine that Florida has a PVI of R+2. So even though Obama won a state that Kerry did not, its PVI actually become more Republican!

4. “Wait a minute, what good is this measure if it decides that a state that went Democratic is actually Republican?”

Think of the country as being the “center”, the “center” might be more Democratic and it might be more Republican at times, but regardless of which one it is, the country will always be at the “center”. The PVI is attempting to tell us how far away from the center a given area is.

5. “Ok, so the PVI is a way of determining where a district is compared to the country, I understand that, but why is it that some districts with Republican PVIs of 10 or greater can sometimes have Democrats representing them (and vice-versa)?”

Former House Speaker Tip O'Neill once said that “All politics are local” and this is what he's talking about. Skilled politicians like Democrats Chet Edwards (TX-17) and Jim Matheson (UT-02) are able to survive in districts that are extremely Republican. Or there are states like North Dakota that, while tending to vote for Democrats for congress but vote for Republicans for president.

6. “Does this make the PVI system worthless then?”

No, since these districts are becoming fewer and fewer as the country becomes more polarized, the PVI is extremely useful in the vast majority of districts. Of course, the PVI does not tell us vital information, like whether or not there are viable candidates in the district, whether or not it traditionally is a split-ticket area, or on how scandals would work.

7. “Ok ok, I get what the PVI is and why it's useful, but why two presidential elections, why not just use one?”

Because using only one set of election data means that the new PVI would suggest that something massive has changed, even if it was only a one time thing. Two presidential elections lets us hedge our bets a bit. For example, we know that Indiana voted 3 points more Republican than the rest of the country, yet we also know that the last two elections had Indiana voting 9 points more Republican than the rest of the country, the idea is that we should not ignore the past.

8. “So then why not be even more cautious and use 3 or 4 different elections?”

My answer would be that, while I could definitely see incorporating three presidential elections into data for a given presidential year, doing this can hedge too much (for example, Gore did 6 points worse in Colorado than he did nationally, Kerry only did 1 point worse than he did nationally, and Obama did a point better nationally, if we did that, then Colorado would have a R+2 lean instead of being considered a D+0). It's up to each individual to decide whether or not more data should be added, but this is mostly the balance between having too much data and having too little.

9. “The PVI is meant for congressional districts, and shouldn't apply to states, yet you keep using states as your examples, why?”

As was mentioned earlier, the PVI is usually only calculated for congressional districts, but that doesn't mean that they are the only thing which has a PVI. So long as we have the data, we can figure out, not only what the PVI for each state is, we can also figure out the PVI of each county and even the precinct level. The reason why I'm not using congressional districts in my example is because the data isn't available yet.

And there is my explanation of the Partisan Voting Index, as a project, I'll probably start calculating the PVIs of each individual state (look for it on Election Inspection).