Zack Smith (The Heritage Foundation) has posted Does D.C. Statehood Require a Constitutional Amendment?: You Better Believe It (Ohio State Law Journal Online 2022) on SSRN. Here is the abstract:
In the debate surrounding whether the District of Columbia should become our nation’s 51st state, understanding the relevant constitutional provisions implicated is key, and there are at least three: (1) the Twenty-Third Amendment, (2) Article I, section 8, clause 17 (the District Clause), and (3) Article IV, section 3 (the Admissions Clause).
More importantly, these provisions shed light on whether Congress has the power to radically transform both the size and status of the District of Columbia by simple legislation. In short, it does not—meaning that in order for the District of Columbia to become our nation’s 51st state, a constitutional amendment is required.