I try to give them one chance. Sometimes I get pulled in deeper if I’ve got nothing better to do. But on the whole, respond with curiosity first. Then determine of they are worth your time. If not, ignore them and move on, interacting with those more worth your while while eye rolling the idiots.

Guess the best way is to not care much about what others think of you. Then, eventually, down votes and bad arguments made by morons really just don’t even bother you. Engage with better people, ignore the rest and chuck a down vote.