DC should go entirely to Maryland. Virginia reclaimed is part of DC around the Civil War. If I remember correctly.
VA retrocession happened in 1847, actually. The original D.C. was a 10 mile by 10 mile square. The VA portion (Alexandria) consisted of about 3!% of the total.
What really needs to happen is a supersized capital district-- DC, most of Northern Virginia within commuting distance of DC, stretching up to include all of Delaware north of the Chesapeake & Delaware Canal. Delaware gets everything south, including the Eastern Shore of Maryland. Maryland cedes everything west of the Catoctin Mountain ridgeline to West Virginia, so there is one big eastern panhandle rather than two little ones.
This makes not only a sensible geographic division, but a cultural division as well.
Hell, we'd (Pennsylvania) even throw in Philadelphia, a former national capital, to seal the deal and retain only a little shoreline between the airport and Marcus Hook for a port outlet. Then we could exchange the Maryland panhandle for West Virginia's northern panhandle.
The end result is that you get one solid left state (New Maryland/DC) and three swing states (Delaware, Virginia, Pennsylvania) no longer dominated by a single metro area.