The thing is, Dems know if they put up a remorseless, possibly effective fight it would change the character of the party, and probably amp up some violence from Trump supporters, and they themselves are too afraid of being the ones to actively stoke any anger from the other side head first. Even when the sole choices are either they back down, Trump wins and there's permanent state violence, or they stand tall, beat back Trump's advancement and there's short-term random violence from his supporters, they will always go with the option that is most passive because that is their fixed and immovable disposition.