If the order to deploy were worded correctly, Posse Comitatus 1878 would not apply...
"The President, as Commander-in-Chief of the United States Armed Forces, has determined that the continuing influx of illegal immigrants and the crime, disease, and drug traffic which follows presents a clear and present danger to the safety, security, and public welfare of the People of the United States.
"Therefore, be it known that elements of the United States Armed Forces are to be immediately deployed along the Northern and Southern land border of the Continental United States. These force elements have tacit authorisation to use lethal force as required to prevent the inflow of undocumented immigrants, and those who would circumvent established processes for entry into the United States.
"These forces will operate under the auspices and policies of the Immigration and Naturalisation Service, Department of Justice, and the United States Border Patrol will be removed from DoJ command structure and be seconded to the Department of Defense for the duration of the illegal immigration crisis.
"DoJ/INS will still retain authority over deportations of detainees and will also maintain control of immigration policy. DoJ/Border Patrol will advise and train elements of the US Armed Forces in the tactics and strategies of border and immigration control, and will operate jointly with the US Armed Forces elements deployed at the land borders.
"At-sea border patrol action will be handled cooperatively with the Department of the Navy/United States Coast Guard. DoJ/Border Patrol agencies will also train, advise, and serve jointly with USCG elements deployed to border operations. However, USCG rescue operations will retain priority, and all cutters and other USCG ships will maintain surface travelling times of 30 minutes from the nearest USCG/DoJ/BP naval vessel.
"These deployments shall remain in force until it is determined that they are no longer necessary to staunch the flow of undocumented aliens. It has been determined by the United States Attorney General and the Department of Justice that these deployments will in no way violate the provisions of the Posse COmitatus Act of 1878, as domestic Law Enforcement operations are neither augmented or supplanted by Federal military forces.
"Be it so ordered by the authority vested in me by the Constitution and Laws of the United States of America, as President and Commander-in-Chief."
FFZ