As for my ideas:

East Coast: The Artificial Intelligence that calls itself Jiù Xīng (assuming I translator this correctly), or "Liberator" in English, is positioned a mere twenty miles south of New York, diametrically opposed to its northern neighbor in pose purpose and intent. Whereas the Economist was designed to make use of and predict the trends of American hypercapitalism, Jiù Xīng was designed to end it from the inside, similar to the smaller Liberator robots of Appalachia, though even more subtly so.

Programmed by Chinese software engineers, Liberator was planted at the very heart of American signals intelligence, a massive supercomputing ZAX complex in Forth Monmouth, NJ, one of the few places in the country that could both accommodate it and supply the communications equipment needed to serve its greater purpose:

To turn the vast number of robots in the United States against the government, hopefully rendering revolution inevitable. Chinese spies across the country - but particularly in New England and the Rust Belt - slipped tiny, highly miniaturized radio receivers and transmitters into the production schematics of both automated and mostly manual robot production facilities across the country, allowing Liberator to communicate with thousands of military and civilian robots by simply adding piggybacked signals to the massive amounts of data pumped out of Fort Monmouth every day; running effectively silent, Liberator was able to avoid detection for years, waiting for the inevitable signal to activate its hidden army at a moment.

That signal never came, of course - a number of the base's personnel that fled the destruction above were willing to join the Liberator for the simple sake of survival as it activated what comms equipment remained at the base, summoning all the robots it could take command of to its side. Once the immediate dust settled, Liberator immediately set to work seeking out internment and PoW camps, freeing large numbers of Chinese prisoners, some of which had been lucky enough to escape ghoulification, death, or torture at the hands of the US government. Over the next handful of centuries, it went to work building a Communist society around Fort Monmouth and the surrounding Ocean County, eventually extending its control further in an attempt to claim what nearby manufacturing capacity it could in order to maintain its army.

Canadian nationalists based of of Diefenbunkers/the Toronto Urban Agglomeration are also an option I'm seriously considering; the best way I can describe them would be as a Canadian mirror of the NCR, but with fewer territorial ambitions.

West Coast: Still working on this, but the basic gist is a resurgent 'Goddess of War' take on Diana, wreaking vengeance on the Legion and trying to restore her tribe in the process. Possibly distinctly matriarchal in reaction to the Legion, minus the, uh... Slavery and shit. Immediate worries are finally securing their future in the turmoil, 'deconverting' her former tribespeople, and probably hunting down whatever's left of the Legion leadership.