Representation for D.C.?
Matthew Yglesias brings up the fact that he is a taxpaying U.S. citizen living in the United States who has no Congressional representation. A sort-of bipartisan* group of Senators and Representatives have sponsored a bill to give DC a voting representative (presumably a Democrat) in the House, balanced politically by an extra representative for Utah (presumably a Republican) that it barely missed out on at the most recent reapportionment.
*The sort-of-bipartisan group includes Republican Senator Orrin Hatch, not-really Democratic Senator Joe Lieberman, Republican Representative Tom Davis, and Democratic non-voting DC delegate Eleanor Holmes Norton.
On the one hand, I can certainly understand how it's kind of sub-optimal that a city of nearly 600,000 doesn't have any real representation in Congress, especially since it's a fully-incorporated part of the U.S., and not a tax-exempt territory. More than just the vote, the District's non-state status means that services and infrastructure in the District that doesn't directly serve the government is something of an afterthought. But on the other hand, this solution sounds like a temporary compromise that still leaves the people of Washington without full state status, is of very questionable constitutionality, and rewards Utah with an extra Congressman (and Electoral College vote) just as a political favor ("almost" shouldn't count in reapportionment).
The comments to Yglesias's post have all sorts of arguments pro and con, as well as alternative proposals. Some suggest turning the District of Columbia into a state. I'm not sure about the interpretation of the clause in Article I, Section 8 of the Constitution authorizing the formation of the federal district, but I think most people interpret it to mean that a non-state federal district must exist. If that is indeed the case, the Constitution would need to be amended if the District were to be done away with entirely; alternately the District could be reduced to simply the Federal Triangle (i.e., the Mall and its immediate environs) and the rest either retroceded to Maryland or become a state by itself.
Getting back to the Constitution, I think the point of the aforementioned clause was to set aside an area for the federal government outside of the influence of any state. I don't have anything against that, but I think it may have surprised the Framers of the Constitution to learn that such a large city had grown within the District's limits. While perfectly legal, it does seem contrary to many of the basic principles forming this country for so many people to be disenfranchised. Furthermore, I think at the time there may have concerns that a state government might conflict with the federal government, but since then the federal government has certainly proved itself capable of operating independently of any states on federal property.
If it were all up to me, I'd probably amend the Constitution to allow the dissolution of the District and retrocede the whole thing back to Maryland, but the people in Maryland might not want Washington and the people in Washington might not want Maryland. It might be more preferable to have the District become a state.
But I think to a lot of people (self included) the idea of the capital becoming its own state just seems weird --- not just because it hasn't been for two centuries, but because aesthetically it just doesn't seem like a state. Its population is very small (though greater than Wyoming and not that much less than a few other states) and its area is tiny. And much more so than in other countries, states in the U.S. are supposed to be kind of like little countries, with fully-developed economies of urban and rural areas working together. The District of Columbia doesn't have any real industries besides tourism, and the museums and such are free anyway. Even more than politics, the lack of a money-generating economy may be the biggest stumbling block to statehood, and would also be a good reason for Maryland to be wary of taking them back on. I dunno how to solve that, but it would probably be easier to absorb it into Maryland than to support itself.