Well we know Trump isn't going to change for the better, so that leave the Democratic candidate as the relevant value for whether our next election is an improvement over the IMHO worst ever choice in 2016.. I'm guessing the Dems won't press their luck with a super leftist candidate because they will prioritize beating Trump over policy purity. Someone like a Tim Kaine, Joe Biden, Amy Klobuchar would seem like the second coming of Winston Churchill next to Trump. Even Corey Booker would probably be a winnable candidate although the margins would probably be closer than the earlier set. All bets are off if the Dems nominate someone who will seem like they too want to completely upend the political order rather than establish the pre-Trump norms, someone like Elizabeth Warren or a retread like Jerry Brown. And god help them if they nominate Hillary again, I don't think any party is that stupid.
Jeez... You go on as if Libs were the ones who elected Trump & a lootocratic GOP Congress.