Biden should have cut off all aid to Israel. At the time he was still thinking of re election and as soon as one show's any animosity towards Israel the propagandists pull the anti Semite card. I think many would have accepted a, "I'm anti Zionist but not anti Semite" statement from him.
That was never going to happen, Biden is an avowed Zionist. Harris should have separated herself from this, but to be fair to her, she had to run an incredibly short campaign. There wasn't time for her to develop her own platform. Not having a primary was a critical mistake.
The situation was fucked from the beginning. Without looking it up I do remember Biden saying in 2019 that he would only run once. If had stuck to that, things may be different. Face it, we have been living in a quite dictatorship since the Gilded Age. Now it's in our faces.