I think this does mark a tectonic political change, but that change will be the end of the Republican Party in presidential races for a couple of decades at least. The Party will split into Fascists and Republicans. The Fascists will win Republican primaries, but then lose the general election. As long as Democrats don't go hog-wild with a Socialist candidate, the Democrats and Independents will vote to defeat the crazy Fascist.

When enough young people who don't remember Trump and his mishandling of pretty much everything become voters, then maybe the Republicans will be back.