Based on polling, Biden loses more voters by defunding Israel than he does by maintaining the status quo

in a close election, there’s very little political rationale to change anything.

Which polls would that be? Because all of the ones that I’ve seen indicate that the opposite is true.

The voters “lost” by doing nothing are most likely not to vote or to vote third party

Tell that to the Muslims and Arabs who got him just barely over the finish line in Michigan and other states he can’t afford to lose.

there is a small percent of voters that will switch to Trump if he defunds Israel

Much smaller than the percentage that will go from voting for him to not voting if he doesn’t.

But anyone that cares about morals isn’t going to change their vote from Biden to Trump

True, but many WILL refrain from voting if there’s no anti-genocide candidate to vote for. I’m not saying that doing so is a goodidea, but that’s what some people will do if Biden doesn’t change course.

If you’re a single-issue voter on this topic, only people who want Israel funded would have a political choice

Except the choice to refuse to participate. Again, not saying that it’s a good idea, just that it’s what many people will do unless Biden does the only right thing both morally and politically.