The same thing that would happen if Harris won: more death. I imagine Hamas also knows they were not going to win a military victory. The victory to be had for them is, I imagine, a moral one: exposing the moral vacuum at the heart of the American Empire (so Israel included). And in that, they have achieved a massive victory without a doubt.
It's disgusting that any Palestinian was killed regardless of administration, but that's the pragmatic reality until Israel ceases to exist. So the question has to be how to achieve that, and I think they've made massive strides towards it. And as for America, it's dying all on its own.
Capitalists are not vulnerable to political pressure from the left because capitalism is inherently contrary to the demands of real leftists. So, my answer to your second question is: neither. And you don't even have to take my word for it: my evidence is Biden refusing to end political aid to Israel and Harris pleading "no change" from that genocidal policy. I mean for fucks sake, Trump even pretended to reschedule cannabis before Biden did!