The protestors want an end to the US facilitating genocide. Most Democrats want fewer, if any, aid to Israel, yet Democrat leadership refuses to budge.
You blame voters for "being willing to let Trump win". Why not blame leadership for hurting their own chances at election by going against their own base?
Obviously less, to the extent that anyone can predict geopolitical events that far in the future. I think the only counter-argument is the idea that an Israel that isn't receiving massive amounts of US aid will be invaded, but I don't find that argument convincing. It's an open secret that Israel has nuclear weapons, and even if the US stops arming Israel tomorrow I don't think Iran or their proxies are dumb enough to think that the US won't come rushing right back in if Israel is invaded.