[Poohbah]

The Posse Comitatus Act prohibits the use of military participation in guarding United States borders?

Does that apply to the Coast Guard?

The Coast Guard is descended from the Revenue Cutter Service, and has a different set of laws. However, its authority ends at the end of the navigable waterway.

[jpsb]

Posse Comitatus Act prohibits the US Army and maybe the US Navy from domestic law enforcement not protected the borders. I am not in favor of an armed border our military has better things to do. I see no reason why the US Mexican border can't operate like the US Canada border. Just implement my two suggestions.