Sometimes, we eat during meetings - or rather, they eat. I can confirm from the food served and their willingness to eat it that very few, if any of them, are vegan. I always decline food but don't say why, but eventually, I'm sure someone's going to ask.
And that's the moment I've been dreading. I've been on Hexbear since it first went online. I've seen, firsthand, how much non-vegans - even the communists here, who have better politics than 99% of the people I know - fucking hate us. I'd go so far as to say at this point that I'd be more comfortable telling an average lib I'm vegan than I would a communist. At least the lib will probably just see it as a strange personal choice rather than accusing me of being a fifth columnist.
Like others in the thread I haven't seen any special hate irl. People are pretty normal about it. On SRA camping trips people sometimes make an effort to make vegan meals like curry even though I'm usually the only one along. And there are whole left orgs like Food Not Bombs that are vegan. Who knows, there might be other members like you who are afraid to be seen.
You have spent more time thinking about this than 99.99% of carnists, so you will probably have a winning response to any sort of questioning/dismissive swipes without actually starting an argument. Carnists probably unconsciously know this too, nobody wants to discuss veganism with me unless they have genuine questions (which I'm happy to answer).