Ideologically, the fact that the constitution represents a compromise with slave holders has become increasingly intolerable for democrats. Anti-racism as a principle has become more important than rule of law or cultivating a shared respect for the fundamental law.
None want to burn it all down. This is for genuine fear of those who want fascism to encourage mob violence, discrimination and deny law and order to minorities.
Puritans are not the anarchists in this story. Little Nazis are trying to normalize revolution and idol worship as somehow universal.
Lying to kill the constitution is their main tactic.
Your left leaning democrats are like our center-left government parties in terms of ideology. The Dems as a whole are slightly center right. Your Republicans are like our far right fringe parties.
Especially after how they handled their presidents insurection, the Republicans in my eyes should be unvotable for anybody who cares about democracy. And they should remain unvotable until they do some soul-searching. But this also includes things the GOP does outside of Trumps sphere of influence. E.g. look at the list of the worst gerrymandered states or at how the right tries to stop people from voting. If not enough people vote your party the democratic way would be to adjust which positions you offer to them, but the GOP seems like it would rather adjust their electorate.
Even if I liked the positions the GOP holds I would hate the idea to let them rule me, because this smells of "ignore what the voter wants". To theie credit, they managed to divide the electorate so much with culture-war bs that a big part of them actively want to become peasants under absolutist rule if it just meant the other side will lose.