10 of 15 richest counties in America are in the DC area

This concentration of wealth around capital city is called the "Crony Configuration".  It's very common in third world kleptocracies. Because in corrupt centralized states all wealth is captured and retained by one's relationship to those who control (as the Sovs used to say) the state organs.

It's interesting to note that the statists are constantly railing against the 'fat cats' who presumably live elsewhere.  So why out of America's 3000 or so counties do the 'fat cats' have only five spread rather evenly across the country while the 'selfless servants of the people' have ten?

 Reminds me of an old children's fable I once read.  It was about a farm:

But just at that moment, as though at a signal, all the sheep burst out into a tremendous bleating of--

"Four legs good, two legs BETTER! Four legs good, two legs BETTER! Four legs good, two legs BETTER!"....

"My sight is failing," she said finally. "Even when I was young I could not have read what was written there. But it appears to me that that wall looks different. Are the Seven Commandments the same as they used to be, Benjamin?"

For once Benjamin consented to break his rule, and he read out to her what was written on the wall. There was nothing there now except a single Commandment. It ran:

ALL ANIMALS ARE EQUAL

BUT SOME ANIMALS ARE MORE EQUAL THAN OTHERS

Yes they can, they did and are doing it today.  

"And the man in the silk golfing shorts crosses the fairway and says 'get a job'."