The Constitutional Convention, by a unanimous vote (12-0), adds a clause to the Constitution for the united States that “[A] republican constitution, and its existing laws ought to be guaranteed to each State of the United States.”
[restored 9/18/2021]
Subsequent Events:
Authority:
Articles of Confederation, Article XIII
ccc-2point0.com/Articles-of-Confederation
References:
William M. Weicek, The Guarantee Clause of the U.S. Constitution, (Ithaca, New York and London: Cornell University Press, 1972), 54.
The Federalist # 43
constitution.org/fed/federa43.htm