You can get a pretty good idea of who people are by examining their history, including on this site. Recent history is more relevant, since people can change.
Snarky comments about marginalized people is a fair indication, whether it's negative comments about sex workers with impeccable reputation, sarcastic remarks about the homeless, false allegations, or what have you.
It doesn't mean they are bad people, but maybe sometimes they do or say bad things. There may be hope for them, but that doesn't mean that it's a good idea to engage with that kind of behavior. Things can get ugly really quick.
https://www.cnn.com/2019/10/30/us/wh...eve/index.html
https://www.lifeafterhate.org/