The way that the merest hint of dissent against Israel has been attacked like a drone swarm, repeatedly twisting fairly benevolent comments into accusations of anti-semitism, in both the UK and US recently has been remarkable. Say what you like about the Israel lobby, they're nothing if not well-organised.
In my opinion, it's like this. If there was to be even a small shift of opinion in the US towards the Palestinian view, and a president in office like a Sanders willing to pressure Israel, then it may have no choice but to agree to peace along the lines of the long-standing international consensus. For the Israelis, this cannot happen. So they are merciless about stamping it out.