I'm probably missing a lot of the words for this, having not studied history nor philosophy of science in any depth, being just some guy that does software and reads stuff... so this is going to be a pretty square and incomplete account of things... so maybe you think about science as an institution, or as a practice. It's an institution made of people, a practice performed by people. We often fail to live up to our best ideals, but they're still our ideals (cf. the USA). Humility in particular would be good to highlight at this sort of event, both to and from the crowd.
I didn't see either of my words anywhere. That's fine. I did see a “Make America Care Again” sign, which was the first MAGA riff I've ever liked.