It would take a constitutional amendment as there are so many prohibitions against making this former small piece of maryland into a state. I could understand if they wanted to let them vote for Maryland’s Senators but even that is unconstitutional.
Not if the land (excep for a small area around the Federal enclave) is retroceded to Maryland, but that requires Maryland's approval and so far, even deep blue Maryland hasn't been willing to take that mess back. After all, it already has Bawlmore.