AS A D.C. RESIDENT AND taxpayer, I’d love to see the adoption of Alan Green’s idea to return Alexandria and Arlington to the District of Columbia (“Diamond Mine,” 4/28). However, as a political scientist concerned with District affairs for many years, I must dump a small pail of ice water on his proposal.

Green seems to have overlooked one vital fact: the Constitution. Article IV, Section 3 of that document gives Congress the power to admit new states into the Union. But Section 3 also provides that Congress cannot take territory from an existing state without approval of the state’s legislature.

This would involve a few complications: Virginia would have to give up one or two seats in the House of Representatives. The state government would have to learn to do without those beautiful tax revenues and federal grants related to the territory ceded to D.C. Virginia residents of the ceded area would have to give up representation in Congress, except for a nonvoting delegate, and join us politically impotent D.C. citizens. I find it a little difficult to envision the Virginia legislature blessing such a plan.

When Congress formed the District of Columbia from parts of Maryland and Virginia, as required by the Constitution, the legislatures of those states had to formally approve the deal. Green notes that after Alexandria County had been ceded back to Virginia in 1846 at the state’s request, “Abraham Lincoln later urged Congress to reannex the land, but to no avail.” After the Civil War began in 1861, some congressmen did recognize that the retrocession had been a mistake. But Congress had no more power then than it has today to reverse the 1846 act without Virginia’s approval.

I, too, have had fantasies about what D.C. might be like today if then-Alexandria County had not been returned to Virginia, or if it could somehow be regained today. Unfortunately, the Constitution is still there.

North Cleveland Park