They wont go away but they will eventually split with the Republican party. The Republicans aren't racist enough which is insane to say, but they arent.... You have Republicans telling Trump to concede and stopping supporting him, and Trumps sons calling them traitors and shyt lmao.
They are going to meltdown, and once that split happens thats IT for Republicans as a party. Dems will grab everything and ram through a bunch of shyt. At that point one of two things happen... Either Bernie Sanders squad becomes the "New Left" wing party and Democrats are the new right; or we end up with 3 parties like in some places in EU.
Possibly but I don't think it will be that simple. The next Trump will be less of a maverick and the DEMs have their own infighting.
If Trump with all of his madness could get close to re-election and might just have won if it wasn't for his extremes and covid, a toned down version would have a good chance.
If a republican outsider embraced populism, toned down the racism and pledged real tangibles the DEMs would have no answer.
Corporate politics (i.e. more of the same) is not the way forward. During difficult economic times it is normal that politics diverge. And this is being magnified this time by the Internet. American corporatism needs to change and there is nothing in this DEM ticket to say that it will. That all hints at another similar round in 2024.
As for the EU surely you have been seeing similar. Right-wing parties are gaining strength all over Europe. Even in the UK (which doesn't have a powerful far-right) the Conservatives have gone quasi-MAGA.
If you expect a return to " 'safe' politics and political rulers as per normal" expect to be disappointed.
Remember the left vs. right extremism leading up to WWII in Germany. These things happen under stressed economic conditions and that is what we are in. The West is becoming increasingly poorer and the borrowing from the future is not producing the desired raise in living standards.