I think the answer is that the media firestorm of rebuking Israel in a meaningful way would be cataclysmic. "Why do you hate Jews?" would be the only question asked of Biden or Harris. I think they think that there is no political cover to act here.

And I think they are right: obviously every Republican would call them antisemitic immediately, as would the ADL and AIPAC. And the media just isn't competent to push back on that. So it's work behind the scenes or else hand the Republicans the election.