[Wonder Warthog]

"The election's real purpose is to protest the fact that, along with children and felons, D.C. residents don't get to vote for members of Congress."

If they don't like it, they should move outside the limits of DC, and vote as citizens of their state of residence. They knew/know up front that by residing there, their "national" voting rights would be limited. No amendment necessary.

[Gorjus]

If they don't like it, they should move outside the limits of DC,

Bingo!

No one should live in the District - not as a permanent (i.e. 'voting') residence. The only real industry in DC is government, and life there should be considered transient. Whether it's an intern working for a Congressman, or the Congressman, or the President, all 'residents' of DC should always remember they're on their way out.

Of course, I wish a lot of them would hurry up a bit.