I'm sure that it's been mentioned here before but I can't find a dedicated thread. Anyway, State Guard units seem like an interesting patron, ally, or adversary for CONUS-based campaigns. State Guard units answer to the state governor and can't be federalized.
https://en.wikipedia.org/wiki/State_defense_force
The New Mexico State Guard, for example, was, up until very recently, a small (about 50 personnel), part-time, unpaid, unarmed force, called on, from time to time, to perform several support roles, mainly disaster-relief. Obviously, WWIII would change that, and I envision their size and role expanding, especially after the TDM.