I've been saying this for a long time, too.
In fact, I'd go further. If we want to create a new "shovel-ready" jobs program, let's convert Washington DC to a museum heritage city and relocate the capital to a new location, say Kansas City, and build it out to handle modern government needs.
Article I Section 8:
To exercise exclusive Legislation in all Cases whatsoever, over such District (not exceeding ten Miles square) as may, by Cession of particular States, and the acceptance of Congress, become the Seat of the Government of the United States, and to exercise like Authority over all Places purchased by the Consent of the Legislature of the State in which the Same shall be, for the Erection of Forts, Magazines, Arsenals, dock-Yards, and other needful Buildings;
Cede the District of Columbia back to Maryland (Congress returned the Virginia portion in 1846) and create a new Government District where we can break the faux "majesty" and sense of nobility that has arisen within our political class from living amongst all the marble splendor.
Build a new capital city that can handle a House of Representatives larger than 430 representatives. Build a proper infrastructure where there are enough offices for staff and other government departments, security, housing, transportation, etc.
Then, when it's done, we can annex Mexico and have enough room for another 20 or 30 states in the seat of government.
-PJ
It would gladden my heart to move the capitol to Kansas City.
If for no other reason, Washington DC and surrounding counties would assume a level of prosperity equal to Detroit.