The demographics are all trending toward the Democrats. New voters register as Democrats twice as often as they do as Republicans ( though more than half register as independents). But, in general, they are relatively liberal.There have been previous situations where one party was the subject of “The Party’s Over” books. But they were able to come back by appealing to demographics that the other party didn’t have in their pocket. The only people that aren’t solidly in agreement with Democratic positions are far left wingers and far right wingers. There aren’t enough far right wingers to win a national election. The Republicans can’t make their tent big enough to include the far left wingers without the people already in the tent setting it on fire. It’s pretty hard to imagine a situation where any of the available Republicans can beat any of 5-8 possible Democratic candidates, and most incumbents are reelected. That means we are most likely going to have a Democratic president through 2024, by which time a huge number of those angry old white guys that are now the bulk of the Republican base are going to be dead.The upshot is that there is a darn good chance that we will never again have a Republican president.