Would you be kind enough to point us to the place in the Constitution where that is spelled out? I am having great difficulty finding any such language in the document.
Article IV, Sec 3.
The process for admission is spelled out clearly. Implied in that is the process to reverse admission. I.E, both parties agree. It is much like a divorce, (breaking a marriage contract) and by breaking that contract, there are property settlements to be made.
How does one reimburse the people of another state if one state decided to secede? What of Federal property in Texas, say the Johnson Space Center, or Fort Hood, that belongs not just to Texas but to people of all the states who paid equally for that property?
The other question would be not with the original 13 states that were created under British Rule, formed the nation by ratifying the constitution and theoretically could revert to nationhood organically, or with Texas, that was an independent nation before they applied for statehood and could presumably revert to that model.
What of the other 42 states that were common US territories, acquired by purchase or treaty by the United Sates (i.e. the people of all the states) who were territories totally defined by Congress well before admission. Where is their standing? They were artificial creations of the United States. If Arizona secedes, does it revert to Mexico?
You are talking about the messiest divorce in history.
Realistically, we are well beyond secession. It won't happen. If Mississippi seceeds, does that mean that Washington can stop sending Social Security checks there? Do all Federal contracts at the ship yard end?
Realistically, we are well beyond secession of any type. It won't happen. But I would argue that if some states banded together, we could nullify some of the more onerous regulations barely implied in Congressional acts being imposed by zealot Federal regulators.
The EPA CO2 limits might be a good place to start. My guess is that the Courts would knock the EPA on their ass if they went after a couple of states that refused to enforce those regs. Even the Court can tell which way the wind in blowing.
I would advise that like minded states band together to invoke nullification of extra-constitutional federal regs being imposed by an out of control bureaucracy as a way to bring true Federalism back.