They’ll go via the path of least resistance. In 2016 this was the Midwest; in 2000 this was the south. They’ll target whatever groups leave the Democratic Party coalition, whatever regions are sympathic to the GOP message, and will adapt their message to create a national coalition.
Absolutely correct.
Given current conditions it will probably be the poorer bits of New England; Maine, Rhode Island etc
This
Agreed.
Maine is the obvious contender - it's generally in the bottom 10 of states GPD-wise, is rural, didn't go strongly for Clinton, and elected Poliquin. On the other hand, in light of the 2016 results as will as Susan Collin's continued landslides, Maine is not solidly blue to begin with.
If the solidly blue states are the west coast states (CA, OR, WA, HI) and the northeast (besides Maine and NH), I'll make the case for Rhode Island.
Rhode Island is probably a distant second in terms of likelihood to turn blue, but given how strong and longstanding its democratic allegiance is right now, it's probably most in the spirit of what the original poster is asking for.
Recent electoral evidence:
* like WV, Michigan, and NH it rebelled against Clinton in the 2016 primaries and went for Sanders - a sign of discontent with the establishment?
* in the 2016 general it and Hawaii were the only dark blue states to swing & trend hard against the dems (the rest of the west trended to the dems and the other northeastern states trended GOP but not as strong as Rhode Island)
Other considerations:
* low economic growth; although not out of line with the rest of New England, this low economic growth is on an already-low base. (I could be convinced Rhode Island is an economic powerhouse like Massachusetts, though).
That this case feels strained is evidence that the core of Democratic coalition is probably pretty stable for the next generation or so, and what's more likely to happen is that the two parties trade around the states that are already swing-y. Our polarized era means there won't be any more VT's or WV's that rapidly shoot from one party to the other.