nobody really backs the Palestinians anymore.
Not what I'm hearing.
Okay, Qatar actually backs the Palestinians and gives them money.
Iran uses the Palestinian issue to poke Israel, but I don't think they really care except as it affects Iran's power projection and weakens Israel. Jordan and Lebanon are certainly interested parties concerned with the outcome, but mostly wanting to get rid of Palestinian refugees in their country and not having more of them come. Syria probably in the same bag as Iran, but mostly their concern is with the East Bank, that is Golan, and Syria is too distracted/weakened by civil war to be much involved.
My impression is that in the Arab world, the Palestinians have largely been dropped. It used to be an issue used to galvanize the public, and keep them behind the gov'ts in power. A distraction from domestic issues. But now domestic upheaval, demands for less corruption and more opportunity and meritocracy has taken hold.
A chunk of the Left in the USofA support the Palestinians, but the Dem establishment is pretty firmly behind Israel, and the GOP is all-in on Israel. So I guess their lifeline is basically Qatari money and some minority sympathy in the US.