I forsee a future where there's an uneasy peace in the Democratic party similar to that which existed during the New Deal days between the Southern faction of the Democratic Party and the rest of the party. The GOP will either die off or fuse with the centrist faction while somewhere down the road (perhaps 5-6 decades from now) the party will split in two.
Wouldn't the fact that the GOP did, in fact, survive that era tend to provide empirical evidence that your hypothetical won't occur?
Possibly. My reasoning is based on the fact that post-millennial Republicans don't consider themselves all that Conservative. Another example here.
The present day GOP is nothing but a combo of racists, religious zealot/nutcases, and true believers of free market Conservatism that was created by historical circumstances that nobody remembers or cares. But this sort of ideology is mostly relegated and propped up by Boomers and older voters. With their political power rapidly declining...the GOP will probably move toward a Phil Scott/Charlie Baker/Larry Hogan RINO type Republicanism which is basically just a dime store Democratic Party.
Another scenario is that the GOP just goes full white power and forever remains the party of angry white grievance but I dont see how this is possible since younger GOP voters dont share their views.
Millennials and post-millennials may not consider themselves conservative, but I don't see how that is relevant to the future; nor do I see how the makeup of the current GOP is relevant.
The problem I have is that you are assuming that demographics change (they will), but that issues will remain static, as if we're going to be debating the same things in 30 years as today. That seems remarkably unsophisticated, which is especially disappointing coming from you, as I've seem some better posts of yours that eschew the tendency of many people here to concern themselves with solely the conventional wisdom.
If we could freeze time in such a way that the exact issues debated now never change but we could also continue the demographic change of the US, then yes, I would tend to agree that the GOP probably would end up going down one of your routes. But these types of predictions reminds of the type that we look back at and chuckle at for being so short-sighted, kinda like those old sci-fi stories that for some reason always seemed to assume we'd have flying cars by now, or like the film 2001- at the pace the space race was going during that time, obviously we were going to have space stations on the moon by now, actually almost 18 years ago by now... of course it couldn't be possible that people would just lose all interest in space travel within a decade, now could it?
Humans are tribal by nature- the history of human civilization is of groups forming based on some chracteristic (identity, resource sharing, whatever), and conflicting with other groups that are either different from them or have competing interests. There will always be people in power and people that do not have it. There will always be two sides of issues, and there will always be issues that divide us. What people call a conservative now won't be what people call a conservative in 30 years, but I'm not particularly sure what is so interesting about this other than pointing out the rather obvious fact that the overton window is always moving.
I do not know what the big issue dividing liberals and conservatives will be in 2050, but I do know there will be one and many of the conservatives then will be undoubtedly ranting about how "I didn't leave the Democratic party, they left me."
Now if your point is simply that the GOP's party platform, as it exists now, won't exist in the future.. well, yeah. OK. Obviously. Then again, neither will the Dems' platform. If this was the only point you were making, then sure- I would agree with it, but I can't say I find anything all that insightful about making this point.