Given how integrated the economy and land use is, it is not a reasonable idea in the near term. If you actually were going to divide the US on a red / blue split then it would be more appropriate at a county level[1] and would result in a bunch of city-states and one big land area[2].

1) states are not really granular enough given the existence of "battleground states" and what that means for election divisions

2) LA and SF might want to buy a desalination plant fairly quickly