Enough of this nonsense, North Dakota had more population in 1930 at 680,845! South Dakota is growing but its very unlikely it will ever get a second district again, unless the US House is expanded. In jest I have decided to recombine these two states in a way that has options.
The recombining of these two states poses some issues. There are a great deal of Native Americans in these two states, splitting the reservations will likely be disallowed, though the counties that the reservations exist in are very low in population but are heavily Democratic by behavior. Combining the two states would see no difference occurring in reapportionment and there would be two districts in the state of Dakota.
Option 1: "Little Minnesota"
Imagine Collin Peterson's 7th District in Minnesota, this is it's mirror image for the most part. In the South Dakota portion the district is 49.1-49.0 Obama/McCain and in North Dakota's portion which includes Fargo, Grand Forks and several Native American counties all along the Minnesota Border. I would recon that this could be partially more Democratic, but not enough to make this district more than a tossup, leaning Republican. Similar to how most handicap Collin Peterson's in an open seat situation. Meanwhile, I think the 1st District (Blue) would be in the low 40's and would be Safe Republican.
This is also much akin to what the former districts ND and SD had when they had more than one seat each.
Option 2: Preserve North/South
This preserves all of North Dakota and takes in Aberdeen and the Native American Reservations. This would be a Republican favored map, where in the South Dakota half would have a 44% Obama percentage but has been 50-50 towards Senator Tim Johnson in the past.
This option I feel would be most likely would occur. Surely the idea of a east/west district would be a community of interest map. But after 122 years of being separated, I would assume stacking the deck to ensure North Dakota and South Dakota would get a Congressman of their own rather than a lock out by one (former) state or the other. Both seats would be likely Republican, Stephanie Herseth Sandlin and Earl Pomeroy are the generic Democrats I am assuming would run in these districts.
Option 3: Democratic Tilt
This map is an attempt to maximize the Democratic voting tilt of the 2nd district. The district is similar to the first option but it adds an arm to include the Native American Reservations that lie in the middle of the new state. This would likely give the district a 52-48 split. It would appear to be a large change but the Native American populations would be small in number of actually turning out to vote, but could make a major difference in a congressional election. This is however based on 2008 and I truly believe this was a high watermark and even with the addition of the reservations it would make the district a Tossup.
Statewide
In real life the states of North Dakota and South Dakota are Republican bastions, the two states gave Obama 44.5/44.75. If the election were to have happened under the unified Dakota in 2008, John McCain would have won at 53.01% to Obama's 44.6% no big surprise here. As for who the Senators or Governors of this new state would be, I will leave that to the readers to speculate.
PS: Doesn't it seem that the two Dakota's were created to ensure Republican electoral votes?