Several years ago, I wrote a diary looking at what might have happened if America had an apportionment rule like Canada's, which prevents any province from having fewer ridings than it did in 1982. Obviously there's no chance of that happening, but there's every chance of DKE readers being interested in unusual hypotheticals.
For my test case, I used Iowa, as it's population has been stagnant for decades and it was easy to find historic congressional district boundaries. Given that, it's therefore no surprise that I picked the Dakotas as a follow-up. However, I got distracted, failed to publish the diary and forgot about it.
A few weeks ago, I happened to notice my old draft. I've now updated it and got it ready for publication. What you're going to read therefore took more than four years, and hence ought to be more impressive than it actually is:
After the 1910 census, both North Dakota and South Dakota received a third congressman. However, at this point both states entered into a process of protracted population stagnation, to the extent that at the 2010 census North Dakota's population was smaller than in had been in 1930. Although rapid population growth has recently returned to North Dakota in connection with the Bakken Shale formation, it remains the 3rd least populated state, whilst its southern neighbour is the 5th least populated. Neither is remotely close to regaining a second congressional district (with North Dakota lost in 1973, and South Dakota in 1983.)
But what if both were guaranteed the representation they had prior to the reapportionment of the 1930s, when both states lost their 3rd congressional districts? How would the lines be drawn, who would benefit and how huge would the House have to become to maintain its current method of apportionment?
South Dakota
If South Dakota were to maintain the entitlement to three seats it had until 1933, the House would have to have at least 926 members, requiring the House to more than double in size. Each seat would have a population of 271,393.
Given that the average South Dakota county has only around 12,000 inhabitants and the median county less than half of that, I've assumed that South Dakota would follow Iowa in not dividing counties between congressional districts. Whilst most states prefer absolute population equality, Tennant vs. Jefferson County Commission establishes that deviations less than 1% are acceptable if they serve state objectives, such as not splitting counties.
As an additional bonus, this makes it easier for me to calculate election results. I'm lazy, what can I say? If you particularly object, imagine there'd be a couple of microchops to restore absolute population equality.
On a presidential level, South Dakota is fairly safely Republican. In theory, you could draw an Aberdeen-Sioux Falls seat that would have been won by Obama in 2008, but a) Romney would have comfortably regained it in 2012 and b) I can't see why Republicans would seek to give away a seat they didn't have to.
I've therefore assumed Republicans would seek to draw a relatively clean 3-0 map, conforming as closely to the 1913 districts as is possible, given population movement.
SD-1 (Blue)
Obama 08: 48.0%
Obama 12: 44.06%
White by VAP: 91.5%
Deviation: -23
Rating: Likely R
In 1913, SD-1 covered twenty-one counties in the south-east of the state and was centred on Sioux Falls. The latter part of that equation is still true, but rural depopulation means the new district now contains only eight counties.
This can therefore definitely be said to be the Sioux Falls district. It's the most marginal of the districts and historically might have been receptive to a local Democrat, but with increased polarisation in recent years it's likely this would be Republican-held by now.
SD-2 (Green)
Obama 08: 46.4%
Obama 12: 41.87%
White by VAP: 92.2%
Deviation: +214
Rating: Safe R
In 1913, the 2nd district was confined to the north-east of the state, but the shrinking of the first forces its modern equivalent south to make up for it.
The largest city in the district is Aberdeen, but with a population of 25,000 that's less than 10% of the district. Rural interests predominate. Partly as a consequence, it's a little redder than the first district and would be unlikely to be competitive.
SD-3 (Purple)
Obama 08: 39.6%
Obama 12: 36.10%
White by VAP: 79.7% Native by VAP: 15.1%
Deviation: -190
Rating: Safe R
In 1913 this district covered everything west of the Missouri. On the 2010 census numbers, that would no longer be enough, so I've added five counties to the east, including the state capital Pierre.
Although this district includes the most Democratic county in the nation (Shannon County, as was), Obama still couldn't break 40% even in 2008. Republicans would have to be beyond incompetent to lose this.
North Dakota
North Dakota is smaller than its southern neighbour, and so would require a House of 1124 seats to get a third district. The target figure is 224,197.
In this case, I provide two maps. The first map has a western district, an eastern district and a Fargo-Grand Forks district. This matches most closely the historical arrangement and would be a reasonable good-government map. The second has an western district, a north-eastern (Bismark-Grand Forks) district and a south-eastern (Fargo) district. This is the Republican gerrymander.
Good government
ND-1
Obama 08: 52.4%
Obama 12: 48.39%
White by VAP: 91.7%
Deviation: +563
Rating: Lean R
In 1913, North Dakota's three districts covered the east, centre and west of the state respectively, with each extending from South Dakota to the Canadian border. However, rural depopulation means that today ND-1 would have nearly 45% of the state's population.
Had the districts continued to exist, it's a safe bet that ND-1 would have steadily shrunk, allowing ND-2 and ND-3 to head east to restore population equality. The logical endpoint of that is a compact Fargo-Grand Forks district, covering only three counties. Although Romney narrowly took the district in 2012, Heidi Heitkamp beat Rick Berg here by over 14,000 votes and it's likely a Democratic congresscritter could have been elected on her coattails, before being swept out again in 2014.
ND-2
Obama 08: 42.3%
Obama 12:38.07%
White by VAP: 93.9%
Deviation: -885
Rating: Safe R
ND-2 covers the eastern part of the state, excluding only the Fargo-Grand Forks area and extending as far west as Bismarck. Although Heitkamp narrowly won here, it's generally pretty reliably red and there's little reason to think the DCCC would ever get involved.
ND-3
Obama 08: 39.0%
Obama 12: 33.00%
White by VAP: 87.3% Native by VAP: 8.5%
Deviation: +322
Rating: Safe R
After years of population decline, ND-3 would have seen strong growth in recent years, due to the development of the Bakken Shale formation. However, the electoral impact of that is limited by a) the transient nature of employment in the area and b) the fact that the area was monolithically Republican before it became entirely dependent upon the fossil fuels industry.
Republican 3-0 map
ND-1
Obama 08: 48.7%
Obama 12: 44.63%
White by VAP: 93.4%
Deviation: +676
Rating: Likely R
Instead of being linked to Grand Forks, this district connects Fargo with counties to the east of Bismarck via counties along the southern border. This is a district Obama couldn't win and which Romney won by upwards of 10 points ought to be fairly safely Republican. Heitcamp did win here relatively comfortably (55-45), but given that she also won statewide, it's not possible to prevent that in all districts.
ND-2
Obama 08: 44.3%
Obama 12: 40.17%
White by VAP: 93.4%
Deviation: -204
Rating: Safe R
Compared to the good government map, ND-2 adds Fargo, losing locally Democratic counties in north-central North Dakota in return. The county becomes slightly more Democratic as a result, but even Heitkamp couldn't break 51% here, so it ought to be relatively comfortable for most generic Rs.
ND-3
Obama 08: 40.6%
Obama 12: 34.41%
White by VAP: 86.0% Native by VAP: 9.8%
Deviation: -472
Rating: Safe R
Less Republican than the good government map, but still far too red to be competitive.
Comments, criticism, verbal abuse? Also happy to take requests for future states - I've got a Michigan map prepared and am working on New York, but would be happy to hear other suggestions.