The federal and state governments have thousands of plans on how to react to possible and theoretical emergencies. In the 1920s and 30s the US Army even had a contingency play for the defense of the US against the Canadians launching an invasion. (don’t laugh, check the “Rainbow Plans” at NARA.)
This is similar plan. And the leftists will take it and raise the alarm that “it is happening now.” The RUMORED plan, as relayed by the “media” and leftist Democrats, also violates Federal law the restricts Federal Military forces from acting in such a role, it is called “The Posse Comitatus Act.”
It is very clear and quite simple:
“Whoever, except in cases and under circumstances expressly authorized by the Constitution or Act of Congress, willfully uses any part of the Army or the Air Force as a posse comitatus or otherwise to execute the laws shall be fined under this title or imprisoned not more than two years, or both.”
And a RAND paper about it: https://www.rand.org/content/dam/rand/pubs/monograph_reports/MR1251/MR1251.AppD.pdf
Thanks for your explanation at post # 14.