It will be interesting to see what happens to the GOP after Trump, in 2028. It's clear that many of them want to turn back the clock, to Bush and Romney.
Nobody knows the future, but one possibility is the GOP becomes a minority 40% party articulating Romney/Ryan/McConnell/Haley that only appeals to those brainwashed ideological idiots who think that Ayn Rand is a great philosopher.
Meanwhile, the Democratic party can then focus on being a right-wing permanent government party, with 55-60% support, it can push for more wars, torture, espionage, tax breaks and subsidies for hedge funds, high inflation that crushes the poor and minorities, and occasionally throw a symbolic bone to its left voter base by taking down a confederate monument, while supporting ongoing slavery internationally and even at home in the case of sex workers.
I don't see that as a desirable outcome, but it's definitely a possible one. I think it's the likely outcome if the GOP chooses to be irrelevant.