Comes right down to it, what will decide this matter is if the commanders of these units consider Biden's order to leave the border open and allow illegal immigration to continue unabated is a legal order. If they decide it is not, they are not required to follow the order and in fact, are required by their oath to defy the order in order to follow the letter of the Constitution... this could get very interesting and backfire on Biden bigly...
Never underestimate your ability to overestimate your ability.
