The percentage of voters who might vote for Biden and support Israel is small and shrinking fast.
The important point is that I do agree that this trend is happening, and Biden is moving in the wrong direction here. His most loyal base has always been pro-Israel, but they’re becoming alienated. He will be forced to pivot soon.
The smart move would have been for him to publicly voice disapproval of Netanyahu but privately continue funding him, for now, with an eye to cutting funding if poll numbers get worse. The fact that he came so heavily on the side of “break up the protesters” was a massive miscalculation. All his career being 110% pro-Israel would have been the smart move, but no longer.