The first one is easy. Article I, Section 10, Clause 3: "No State shall, without the Consent of Congress,...enter into any Agreement or Compact with another State, or with a foreign Power..." The third one is easy as well, and is covered by the same clause since adjusting borders requires agreements between the states. The second one is just as easy. While there is nothing in the Constitution that prohibits secession, unilateral actions like leaving the Union would be prohibited since Congressional approval is necessary for changing the status of a state.
Again, the people of each state are not bound by the Supremacy clause.
They are, but more specifically their legislatures are. And legislation passed by Texas in support of secession, and in support of the rebellion, was unconstitutional.
A citizen of the state could sell land to a citizen of a foreign state of nation. The state could pass legislation removing the area from it's jurisdiction. No agreement of compact with another state necessary. Borders reduced or enlaged, Congress out of the loop.
While there is nothing in the Constitution that prohibits secession, unilateral actions like leaving the Union would be prohibited since Congressional approval is necessary for changing the status of a state.
Congressional approval is necessary for adding NEW states, forming a NEW state 'within the Jurisdiction of any other State', or forming a NEW state 'by the Junction of two or more States' [a merger], or forming a NEW state from 'parts of States.' There is nothing, like you stated, in the Constitution that prohibits secession.
They are, but more specifically their legislatures are. And legislation passed by Texas in support of secession, and in support of the rebellion, was unconstitutional.
No. The people of each state are not bound by the supremacy clause. They are not ALL 'Members of the several State Legislatures', nor all 'executive and judicial Officers' of the state. The state of Texas did NOT pass legislation seceding from the union, the people of the state of Texas in convention seceded from the union.
This raises two questions:
1. Why then did the Founders not mention secession when laying out parameters for admission, dividing into two or more new states, etc.? Why would they be so explicit regarding the incoming and division, but silent (yet implicit in your honest opinion) about the outgoing?
2. Secession is not addressed explicitly in the United States Constitution, but you present secession as not being prohibited by the document (which it most certainly is not), and then you string the implicit nature of its legality further by noting a Constitutional distinction between unilateral and multilateral secession. If you (and supporters of the act) can imply secession as a right of a state by saying its not prohibited (and supporters would also invoke the Tenth Amendment to further bolster their argument), how (without citing Article IV Section 3) can you then imply a Constitutional distinction between the two forms of secession (and I say without citing Article IV Section 3 because it is explicit on admission, etc., yet silent on secession)?