If Democrats knew they’d lose for supporting genocide,.they wouldn’t have done it. It’s precisely because blue-no-matter-who voters convinced them that they were invincible that they ended up losing. They thought they could bully the base into voting for them because enough of the base was willing to be bullied and proud of it.
On the other side, Trump is more likely to lose the war on Palestine.
They were in a bubble of other blue-no-matter-who media and were assured by the consultants from Clinton’s campaign and the Labour Party that they could ignore those polls.
So really, it would have taken a big enough push from the public that MSNBC became anti-genocide. Hypothetically it could have happened, but the Democratic base is too disorganized to pull that kind of bottom-up messaging coup off.