1. Is there a law forbidding any State of the "Union" from deciding to secede from the Union ? Yes. The Alien and Sedition Acts (latter doesn't
apply in KY or VA)
2. Is there a clause withing the Constitution that forbids any State from seceding from the Union ? No
3. Is there a right in the Constitution that allows for any rights not given to the central government to belong to the States, and would that also
mean States do have a Constitutional right to secede from the Union if they choose to do so ? Yes
But if you REALLY want some "teeth" to bolster a State's right to seek their own destiny, you'll check out the language that Thomas Jefferson
included when he framed the Kentucky Resolutions of 1798 and the language that James Madison included when he framed the Virginia Resolutions of 1798
& 1799.
en.wikipedia.org...
The resolutions opposed the federal Alien and Sedition Acts, that extended the powers of the federal government. They argued that the Constitution was
a "compact" or agreement among the states. Therefore, the federal government had no right to exercise powers not specifically delegated to it and
that if the federal government assumed such powers, acts under them would be void. So, states could decide the constitutionality of laws passed by
Congress.
A key provision of the Kentucky Resolutions was Resolution 2, that denied Congress more than a few penal powers:
That the Constitution of the United States, having delegated to Congress a power to punish treason, counterfeiting the securities and current coin of
the United States, piracies, and felonies committed on the high seas, and offenses against the law of nations, and no other crimes, whatsoever; and it
being true as a general principle, and one of the amendments to the Constitution having also declared, that "the powers not delegated to the United
States by the Constitution, not prohibited by it to the States, are reserved to the States respectively, or to the people," therefore the act of
Congress, passed on the 14th day of July, 1798, and intituled "An Act in addition to the act intituled An Act for the punishment of certain crimes
against the United States," as also the act passed by them on the -- day of June, 1798, intituled "An Act to punish frauds committed on the bank of
the United States," (and all their other acts which assume to create, define, or punish crimes, other than those so enumerated in the Constitution,)
are altogether void, and of no force; and that the power to create, define, and punish such other crimes is reserved, and, of right, appertains solely
and exclusively to the respective States, each within its own territory.