Cities in North and South Dakota are so small, though. I don't see how you could include Sioux Falls or Fargo in a map like this. You'd have to include about twenty cities in Texas. (Des Moines's inclusion is suprising to me, but the Des Moines area has almost as many people as all of North Dakota.)

When you're talking about any sort of economic or tax impact, cities of around 100,000 people are barely a suburb on a map like this. Hell, even after the super-charged growth of the last decade, the combined GDP of North and South Dakota is less than $100 billion. The Minneapolis metro area's GDP is over twice that.