I fully expect the Democrats going forward will resemble the GOP's coalition at the turn of the 19th century. A party made up of Freedmen, Progressives, and wealthy WASPs.
Or in the modern sense Minorites, Berniecrats, and Liberal/Moderate Elites bound together by the social desirability of appearing open-minded and charitable. Whether we have a Taft v. Roosevelt style showdown between the more conservative and liberal faction of the party. Only time will tell.
Great analysis! I see a lot of parallels with the Third Party System. The fallout of the Great Recession and the COVID-19 recession, among other failings of Reagan Era policies, are collapsing the current Republican advantage as the Civil War and the Panic of 1893 did for the Democrats then. The Republicans will have their Redeemers in the form of right-wing populists and Bourbons via moderates, with the Kim Klaicks representing the same creeping advantage over a span of decades as Catholic immigrants did for Democrats in the North. Eventually the contradictions in the Democratic coalition will become apparent. You can't have the gentrifiers and the gentrified in alliance for long before people start asking questions.