Where they are at right now is that they can't take any risks on this issue. A lot of people were talking about how there was no Palestinian speaker at the DNC even though the uncommitted movement offered speakers and speeches to be vetted.
From where they were standing though, they likely imagined the person getting on stage, making the speech and then at some point going off script and calling out Joe Biden for refusing to stop arms shipments, refusing to actually clap back at nutanyahu and failing to defend students being brutalized for speaking up for the palestinians. Then going after Josh shapiro and the other attendants at the convention who clapped when satanyahu tried to make a case for his holocaust to continue while visiting DC. The speaker would of course be 100 correct and spitting facts, but it would destroy the mood and ruin the hype meant to be generated by the convention. Once an archer's arrow is loosed from its bow, it is no longer in their control and what the speaker does when on stage would be out of their control. They cut the mic? they're silencing free speech. Let the person speak but the crowd isn't feeling it or they get booed? that's all that's going to be on the news next week. There's no way where allowing this to happen would have worked out well for them.
The survival of their party, and many people represented in the party (like the LGBTQ and black people, spanish speakers etc.) would be sealed if trump won again and they can't take that chance by letting the public feel like this party is hypocritical and won't do something on this issue, or that they will do something which will anger the many conservatives they've been successfully stealing from the republican party who might have stayed home on election day.
The SCOTUS essentially allowed a president to have his opponents assassinated. You think Donald Trump wouldn't do that shyt after January 6th where his morons literally tried to kill people? You've got one group that will at least say they want a ceasefire and admit that what Israel is doing is horrible and needs to stop, while on the other side that isn't even a topic up for discussion.
Kamala Harris ran to the left of Joe Biden in the 2020 primaries. She can be convinced, he can't. If she survives to election day and wins, then we'll see what happens then. Until that time, Joe Biden is still president and this is an issue he needs to be pressured into dealing with. Especially if he wants his party to win the election. It is within his power right now to tell the American people that Ukraine is making gains in Russia so he has no plans to give Israel anymore supplies because Ukraine needs it now as it's taking territory back from Russia. He could do that right now and that needs to be the plan. Get him to do that, and an election win is as close to guaranteed as you can get.