Rhetoric is almost as important as policy. If you see your leaders back down, your only option is to be mad at them and assert your right to what they capitulated on, or tell yourself that you don't really need it after all. An actual leader doesn't stop fighting because they lose or don't have the votes, they fight for the public mandate that will make up this difference in power and it becomes a larger fight. This is what Mamdani did instead of capitulating to the party that told him to stand down. The democratic leaders should be more like him, and less like whatever the fuck they're trying to be right now.

If you can excuse schumer and jeffries not endorsing Mamdani that's certainly a stance you can make, but having such low standards as to openly support them can't be good for your psyche. I'd rather vote for them and outwardly hate them, because being able to do math and tell a fascist from a neoliberal isn't the same as an endorsement, which you seem confused about.