[Publius Valerius]

It has the power delegated to it by the Constitution, not the states, per the 10th Amendment.

Ok, sure. Of course the States created the Constitution, but sure.

But the Constitution does delegate the sole power to create states to Congress. By implication doesn't that mean Congress can also uncreate states?

No. Congress is of limited powers, and if the power is not expressly granted by the Constitution, then Congress doesn't have that power.

And if you look at Article VII, then it appears that the states can.

Yes, as I mentioned on my last post, states can unilaterally expel other members. Congress, however, cannot.

[Non-Sequitur]

No. Congress is of limited powers, and if the power is not expressly granted by the Constitution, then Congress doesn't have that power

Nowhere is the word 'expressly' used in either the 10th Amendment or the Constitution as a whole. It says powers not delegated by the Constitution or prohibited by it. Powers granted, as Chief Justice Marshall noted in McCulloch v. Maryland, can be identified by a common-sense reading of the whole. The Constitution expressly allows for funding an army and a navy. Does that mean that the air force is unconstitutional? No, becuse the Constitution also says that one goal is to provide for the common defense and implied in that is authorization for an air force if that is needed. The Constitution says that only Congress can admit a state, and once admitted Congressional approval is needed to split, combine, change borders, or any other change in status. Implied in that is Congressional approval being needed for the ultimate change in status, leaving altogether. And if not for that, then common sense says that if all states are parties to the compact then all states should have a say if the compact is to be broken.

Yes, as I mentioned on my last post, states can unilaterally expel other members. Congress, however, cannot.

How would you expect the states to act except through Congress?

[Ditto]

Yes, as I mentioned on my last post, states can unilaterally expel other members. Congress, however, cannot.

Under what body, other than the US Congress, would the other states use to expel another state?

As I read the Constitution (Art IV, Sec 3) both congress and the state(s) involved must both consent in either the formation new states, or changing the boundaries of existing states.

Ergo, neither unilateral expulsion nor unilateral secession is Constitutional. Both Congress and the state(s) in question must agree to either.

But what the heck. If you're taking the ultra-libertarian (or radical leftist) position, those pesky constitutional clauses can just be ignored.