And kudos to Dick Lugar for joining Democrats in voting for it.
That said, Robert Byrd didn't, and quite possibly for the right reasons. The move may be indeed be unconstitutional.
D.C. should be reduced to the size of the area immediately surrounding the White House, the Supreme Court and Congress, with the rest folded into Virginia and Maryland. Republicans like Lamar Alexander (who, naturally, claim they want DC incorporated only into Maryland and not battleground Virginia) should be called on their bluff.