1. Article 4 section 3 states a new state can't be made from the territory of an existing state without the state's permission.
2. Article 1 section 8 clause 17 states that the federal capitol is a federal district. So does that mean DC would be a "federal state?" Or would the Capitol have to be moved?
IMO an amendment is needed. Its so obvious it slaps you in the face.
Since D.C. is a is a federal district, not a state, it doesn't need permission from a state because it isn't part of a state. At least that's how I read it. I don't see why they don't just ask to get taken into VA or MD though. Why go to all the effort to create a state, a state legislature, a state constitution, the whole apparatus when it's nothing but a city. It already has a city government, although Congress can override it if it feels it must. If it becomes a state, Congress couldn't do that, either. It would be on state ground.
Interesting. How did the vote go?