Northeast region, continuing along the Great Lakes as far west as Chicago or Minnesota -- it's pretty solidly blue.
West coast from California up to Seattle -- pretty solidly blue.
From Idaho to Kansas, to Texas, to Florida, to West Virginia and the Carolinas -- one very big area which is pretty Red.
There would be outliers (Virginia, New Mexico, Florida etc.) which might be awkward to absorb, but by holding the interior together, the low population center could maintain strength while making it difficult for the two Liberal areas in the East and in the West to unite and coordinate.
But, yeah, 5-6 nations is conceivable. In my opinion, however, that would be more likely to result in actual fighting, because people start thinking they can "win" and control people who don't want to be controlled.
I can see the cleveland to chicago belt, but get 70 miles out and it changes quick.
Other option I see is a split City/Country along what your hinting at. So Seatle to San Diego but nothing inland, Boston to DC/Baltimore maybe Richmond with a finger to Chicago through central PA - though the PA T may have something to say about it. Then it would end up like 3 with maybe a few short-lived city-states like Miami, St. Louis, NO, and Denver thrown in for measure.