“But if the claim is that states can walk out at will because it is not explicitly forbidden by the Constitution then why can’t they just proclaim themselves states since that’s not explicitly prohibited either?”
The way states are added is spelled out in Article IV. For some reason the founders did adopt the way you prefer.
For the record, Lincoln did add West Virginia on a whim in violation of the United States Constitution. So there is that.
“For some reason the founders did adopt the way you prefer.”
I wrote that wrong. It should read: “For some reason the founders did NOT adopt the way you prefer,”
It says new states may be added by Congress. It doesn't say that's the only way, i.e. "new states will be added by Congress" or something indicating that only one method is possible. If it isn't explicitly prohibited then it must be allowed; isn't that what you all keep telling us?
For the record, Lincoln did add West Virginia on a whim in violation of the United States Constitution. So there is that.
No there isn't. There was nothing unconstitutional about the way West Virginia was admitted.