Democrats have always been “the big tent” party, which is part of their weakness, as their voters have a wide range of “demands” that are often, if not always, contradictory. You have to remember that this is a party that has to appeal to religiously conservative black people, while also appealing to upper middle secularists. They are trying to appeal to both conservative religious muslims, and at the same time the powerful voting Jewish bloc.
It’s not an easy tightrope to walk, but it’s not regularly “ignoring demands of the party” it’s “which of these two competing demands of our party can we ignore that will hurt us less?” They basically try to appeal to the voter, but that’s impossible because they are trying to please too many disparate groups at the same time.
Republicans have the advantage of having to appeal to a smaller group and set of beliefs, and then just get everyone else to fall in line behind it (although that is being tested now with MAGA delusionalists vs the traditional conservatives). Republicans have been pushing this fear of different people (immigrants, different religions)and liberal elites for decades now (as you note in another post, via things like right wing media). . . it’s just that they lost control of it when someone (Trump) rose up and fully embodied the id they had been fostering. . .and now they are just following the playbook where they have to get everyone to fall in in line behind that.