Edit: You should really examine how you can hold me responsible for what may possibly happen to all those people you listed, purely based on how I do or don't vote... while at the same time categorically rejecting any responsibility of the democratic leadership for supporting the genocide in Palestine.
I don't care what the dem leadership says about it, nearly as much as I care what they do about it. That the Biden admin and the rest of the dem leadership have real power to stop Israel, yet don't do it is materially the same thing whether they wring their hands about it or not. Maybe the confusion is around the word "support". I don't mean it in the sense of like, thoughts and prayers. I mean "support" in the sense of send offensive weapons, block any hostile measures by the UN and run interference on public demonstrations against your genocide. Plenty of dems fit the second meaning. The first meaning is irrelevant.
You're grasping for justifications where there are none. The US could very well guarantee Israel's security from Iranian attack the way it is doing right now: by parking a carrier strike group nearby. Incidentally, we could use those same assets to simultaneously enforce a no-fly zone over Israel to prevent further bombing. Beyond that, Israel guarantees its own continued existence by way of a nuclear arsenal.