That sounds like something somebody would say if they knew absolutely nothing about the Left (or were just trying to scare/motivate their own base). The Left are ok-ish at organizing when they’re motivated enough, but they can barely agree on anything and will find any excuse to get into a fight with each other. You’ve got people on the Left willing to virtue-signal about Israel, vote third party and lose the presidency to Trump, a candidate who would make things demonstrably worse for Palestinians and would likely increase aid to Israel and remove any lukewarm constraints that the current administration is limp-wristidly raising. Meanwhile, Republicans will overlook any of the hundreds of things wrong with their candidate and compromise any values they’ve had, just to elect the biggest shit stain in history because they know he’ll make the other side feel bad.