Do not shy away from historical comparisons in regards to animal agriculture!
When people get offended at the comparisons drawn between slavery, the holocaust, and animal agriculture, it is not because these are unfair comparisons. It's not truly because they are insensitive to certain groups of people. History is what it is. And it belongs to us all as an example to learn from. People get offended by these comparisons because it is deeply disturbing to have to confront the reality that the same evil that allowed slavery and the holocaust to happen still exists inside of humans. And it is most disturbing to those that are willing participants in the perpetuation of these horrors in their most modern form: animal agriculture. So, please do not shy away from these comparisons (though I would urge that no one try to compare the -suffering- of any two individuals or to suggest that being part of any group means that someone should be more aware of the injustice they are committing - as people are people regardless of how their ancestors or even they themselves are unjustly treated). But, if you focus on the forms of oppression and the methods used and brutality incorporated, these comparisons are exactly the kinds of observations that we need to be making so that we might learn from the horrors of the past. And if someone is deeply offended, there is a 99.9% chance that the offended person is actually offended to have been forced to discover that they are capable of being as unjust as those we demonize in the history books. We must learn from the past or we are doomed to repeat it!