For the entirety of this century, Democrats have been naive institutionalists while Republicans have been destructionists. Institutions cannot save you if they do not exist. Conservatives are trying to kill us while liberals are still bitching about following the norms.
It feels like Democrats think norms are self executing rather than requiring constant reinforcement and maintenance. This is weird! It's a norm violation! It's uncomfortable to treat this as normal! But if the opposition party treats a no big deal, well, it can't be that big of a deal, right?