Which states will shift Republican over the next few decades?

[Snowstalker Mk. II]

As the socon wing dies, I presume parts of the North will become more competitive--maybe Jersey, definitely Maine and New Hampshire.

The Dakotas will become more Republican at a congressional level.

In fact, given all of this, I think California could even become more competitive in the future, while the Appalachian states and the Rustbelt become more Democratic.

[Snowstalker Mk. II]

The socon wing will become stronger... not die off because of the infusion of Latinos. Blacks will not vote in bloc for the democrats for much longer.

Hispanics integrate; new generations are already more liberal, and most Hispanic Democrats are also socially moderate to liberal. When they integrate, they move towards the social norm. Combined with an overall trend towards secularization, the Republican Party norm will look less like Mike Huckabee and more like Paul Ryan. Blacks probably won't always vote >90% Democratic, as the Southern racists die out. However, most are in comparatively poorer urban or Southern rural areas, and therefore would be voting more for the party of the working man (and yes, I'm predicting a more populist Democratic Party).