That act is a complete farce, a piece of feel-good law that is essentially nothing (WRT the common-knowledge that the Army can't be used domesticallt):
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.
Whereas Art 4, Sec 4 says:
The United States shall guarantee to every State in this Union a Republican Form of Government, and shall protect each of them against Invasion; and on Application of the Legislature, or of the Executive (when the Legislature cannot be convened), against domestic Violence.
and Art 1, Sec 8, Cl 15:
To provide for calling forth the Militia to execute the Laws of the Union, suppress Insurrections and repel Invasions;
See: 18 U.S. Code § 1385 - Use of Army and Air Force as posse comitatus
Shepard Smith and John Roberts discussed the possibility that President Trump could exercise the INSURRECTION ACT OF 1807.
” suppress Insurrections “