In what states does current growth and demographic changes favor Republicans?

[Skill and Chance]

1. Retiree resort areas, so FL and coastal SC/NC most prominently.

2. Declining birthrates and enrollment point to structural R improvement in college towns (albeit from a very low base), particularly those with non-elite private colleges.  This would show up first and most clearly in rural New England.

3. Oil and gas boom areas, but it's so cyclical that it could net out to 0 over the long term of booms and busts.  If there's a case for this, it would be strongest in the Permian Basin area of TX and Eastern NM, where conditions are so favorable that it can still be profitable through the downturns.

So that's Florida, the Carolinas, New Mexico, and maybe Northern New England. 

[Skill and Chance]

If Des Moines were to go full Madison, would Iowa be colelatgive again, even if Demc continue to slide in rurals? Issue is it isn’t as much college-based but still just food for thought

No, people tend to overestimate how much one area can move the margin—this only works if its share of the overall population is similar to Metro Atlanta or the Twin Cities.

Even if you apply the most generous, preposterous scenario and shift each of Polk, Dallas and Story's margins 35% to the left without even touching the rest of the state, Trump still outright wins. Altogether, those three counties only cast about 20% of the state's votes, and it would take like half a century for it to even reach 1/3. Bliowa is impossible if rurals continue swinging right

Yes, this only works in select cases.  This is also why NC still hasn't flipped.

Applying the RGV trend to Clark County, NV though...