So there was a mention of a strong 3rd party for that year.
The idea behind this map is that the Democrats solidify their support with minority groups (African Americans, Latinos, ect) as well as most left leaning folks. The republican party gets pulled further right and in the end, moderate republicans split off to form a sort of moderate conservative/libertarian leaning party shown here in grey that's more competitive outside the ideologically pure and shrinking base of the old republican party. The new moderate party is helped by the leftward march of the democrats over the years and ends up picking up most moderate and conservatives outside the south. Third partys have never done well in the south unless they were based there, but still, the combination of this new party and demographics shifts, pushes the region to be more competitive overall between the dems and repubs.
A couple things that people might try to call me out for:
Mississippi-3rd party influence and the fact that the youth vote here is very democratic leaning today could easily put it in the dem column by 2040.
Texas-Growing latino population but maturation of the cities could do this.
Connecticut/Rhode Island-The new moderate party ends up filling the void that moderate republicans once filled, and opts to take a big anti-corruption stand (and has credibility on the issues) to help grab these two.
New Hampshire-So the moderates get CT and RI, why not NH? Easy, by 2040, NH will be about where Rhode Island is today in being effectively a bedroom state for Boston. Add in the seepage of liberalism from Vermont and you got a solid dem state.
Utah-I gave it to the new party mostly because the republicans having not done anything for the mormons of the state in a while and thus they jumped at a chance to try a different alternative to the democrats. To be honest I don't know enough about Utah to really pin it down well.
Montana-I have this weird feeling that Montana might turn into another Vermont situation. Once solidly conservative, but because it was far enough out of the way and had the space, gets invaded by dems whom eventually saturate the politics. Probably moved from California. Folks wanting something a little less arid then NV, AZ, or UT, and not as urban as Colorado will likely be by that point.
Hope people like it!
