I think you're a bit too pessimistic on American attitude to what's happening in the Middle East. A majority of Americans oppose what's happening to the Gazans.
Of course you cant just campaign on Gaza as a single issue - that'd get you nowhere. But as part of a package of progressive policies it takes its place.
One of the major conclusions the Democrats will draw from their inquiry into what went wrong will be that they failed to take on board significant but marginalised groups like Arab-Americans and underestimated the toxicity to their ow campaign of critics of an unethical foreign policy.
Next time will be all about presenting a clear difference between themselves and the mouthpiece of Trumpism presented to them as an opponent.
If a majority of Americans oppose what's happening in Gaza, which I generally think is true in an abstract sense, then why did they just vote for an Administration that, pretty much all parties objectively believe, will make things demonstrably worse for Palestinians.
So in order for both things to be true it's because it's not top of mind for those voters. They're like, yeah in a perfect world I wish that stuff wasn't going on over there, how terrible.
Then quickly they move on to why can't these people just speak English at the CVS down the street, how are my investments doing today, wow that tank of gas I just bought for my $90K house on wheels just cost me $100, and man I gotta call my internet provider again b/c it's not working - the world is ending.
They just don't care enough to make it an issue that moves the dial. Really