Although there was a recent AP article alluding to the race in South Dakota tightening up, I don't think it will be all that close.
One thing to keep in mind is that the same "tightening of the race" theme was echoed in the media just before the North Carolina, Mississippi, and Wisconsin primaries (in addition to other ones). And as well all know, the outcomes of those primaries were not close.
There are several factors which one must take into account when discussing a possible big Obama victory in South Dakota.
1. Neighboring states.
Obama won the neighboring states of North Dakota, Nebraska, Wyoming, and Minnesota by huge margins. Huge. Granted, these states all had caucuses, but Minnesota and North Dakota run their caucuses much like primaries. In any case, Obama has done extremely well in the Western states.
2. Obama's campaign stops.
It has been mentioned that one can tell how the Obama campaign thinks it is doing in a particular state by looking at the cities in which he campaigns. Between today and tomorrow, Obama will campaign in three places in South Dakota: Rapid City, Aberdeen, and Mitchell. If he is visiting a smaller city like Mitchell, which seems more favorable to Hillary, it leads me to believe Obama thinks he can take South Dakota by double digits. It is reminiscent of his campaign stop in Pendleton, OR, a small city where Hillary was favored.
3. Polling numbers.
The only poll that has been conducted in South Dakota shows Obama ahead 46% to 34%. http://www.argusleader.com/...
True, this is a very old poll. But it broke shortly after the Reverend Wright fiasco (part 1) and so it would seem that Obama's support in South Dakota is quite solid.
4. Ethnic considerations.
As I mentioned before, there seems to be a link between German and/or Scandinavian influence in a particular state and Obama's success there. Oregon, Washington, North Dakota, Utah, Idaho, Colorado, Minnesota, Iowa, and Wisconsin all have relatively high percentages of people of German or Scandinavian background. And Obama won all those states, some of them by huge margins. South Dakota is 15.3% Norwegian (3rd in the U.S.) and 3.9% Swedish (5th in the U.S.) so it is clear that South Dakota has one of the strongest Scandinavian influences in the U.S. On top of all this, South Dakota is 40.7% German.
At 8.8%, South Dakota has the third highest percentage of Native Americans. Native Americans make up a large portion of the Democratic base in South Dakota, and I have seen no polling among this group with regard to the current Democratic primary. My sense is that they would be more likely to vote for Clinton, but I really don't know.
5. Education.
South Dakotans have a high school graduation rate of 84.6% which is higher than the national average of 80.4%. However, they have a lower rate of persons holding Bachelor's degrees - 21.5% as opposed to the U.S. average of 24.4%. This is extremely similar to corresponding statistics from North Dakota (where Obama won 60% to 37% in a caucus) - 83.9% of people in that state graduate from high school and 22% graduate from college. If Obama ends up winning by 20 points or more in South Dakota it will be somewhat indicative of what would have happened there if a "real primary" had been held in North Dakota (and by extension, other western states).
One important factor to keep an eye on is median age. South Dakota's median age is 37.3 as opposed to the national average which is 36.4. However, North Dakota's median age is 37.1. Another consideration is that South Dakota is 50.2% male as opposed to the U.S. as a whole which is 49.2% male.
My very first prediction was that Obama would carry South Dakota by more than 20 points. But with the Clintons campaigning as hard as they have there, and the Argus Leader newspaper endorsing Clinton, I am predicting a 14 point victory for Obama. It could be smaller though.
South Dakota has one Congressional District.
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I did not create a homemade map for this particular prediction. But what I did is circle the areas of this South Dakota map where I feel Obama will do particularly well:
Pennington County in the west end of the state is basically the Rapid City metro area. I don't think Obama will lose Pennington County but it could be very competitive there.
Pierre is the state capital and it should go heavily for Obama. I got a speeding ticket there last summer and was not incredibly pleased about it. :(
Brown County is Aberdeen. I don't expect Obama to have a real tough time there.
Brookings County (county seat - Brookings) should be massive Obama territory.
Minnehaha County is the Sioux Falls metro area and holds 25% of the state's population. Obama has already done two large rallies there and I think he'll carry the county by 15-20 points.
Union County/Southeast is the Sioux City, Iowa metro area. Obama shouldn't have a problem there.
UPDATE: I forgot to circle Yankton County! That should go very strongly for Barack.
The bottom line is that if Obama gets to a 20-point margin in Minnehaha and Pennington counties and an even higher margin of victory in Brookings, it will end up being a total blowout. I am sticking with my 14 point margin though.
And now, for those of you who have not visited South Dakota before, here are some lovely pictures.
No trip to South Dakota is complete without a pilgrimage to Mount Rushmore.
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And then there is my personal favorite town, Deadwood, which has a lot of fun casinos and a charming little downtown area, not to mention the surrounding beauty of the Black Hills.
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The highway which goes through Spearfish Canyon has to be one of the most gorgeous causeways on earth.
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Here is Rough Lock Falls in another area of Spearfish Canyon.
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And last but not least, the fascinating Mitchell Corn Palace of Mitchell, which is on the opposite (eastern) end of the state from Deadwood, Spearfish, and Mt. Rushmore. Some of the murals on the building are made out of corn.
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If you haven't been to South Dakota before, don't these pictures make you just want to jump in the car and drive there?