I read the whole thing and OP you disappointed. A number of things to highlight here.
1. Unfortunately, I don't think you've put up much of an argument outside of the mention of police brutality, your responses were just emotionally charged "I hate your very being" "You're evil" type of responses. Very little debunking of his very easily debunk able outlook. I'll give you one for free that immediately came to mind when he stated something to the effect "You see all these stories in the c00ntown reddit and you'll understand my feelings". This is blatantly playing into the issue of confirmation bias on his part. Of course its going to seem like numerous blacks are committing crimes when you get your fukking news from a place called c00ntown lol. Understandably, I understand your emotions, don't get me wrong, but it was not effective in making him look like an idiot.
2. I would really look into debating generalities by actually flipping the generalities on their head, and not even addressing the factual nature of what they're saying at first. What I mean is, someone says "look at this stat, 40% of welfare recipients are black, and therefore I'm justified in feeling black people as a whole are xyz". Well you take the 40% and say "well that means 60% are not, so how can you logically justify judging an entire race on said statistic when it doesn't even account for the majority". After doing that, you then start to hit them with the counter arguments and statistics. For example, the fallacy in using incarceration rates to prove inherent criminality when other statistics show that police disproportionately target certain groups so of course their incarcerations will be higher just because of that. For example, in New Jersey during the 90's, 80% of traffic stops with searches were minorities yet, those found with drugs in their cars were more often white. It shows a disparate in targeting that doesn't even reflect true crime patterns. This is the type of arguments you need to be giving.
However...here is the rub, this is all predicated on the fact that you can change these people in how they think and like already stated, you can't. So even if you did all the above, it won't make a difference and you're wasting your time. Secondly, you're falling into the trap that simply because he seems "more rational" that he should therefore be less racist. This is a false premise to have. Everyone from your college professor to the hill billy hick has the ability to be racist. Unfortunately, I think this is something individuals tell themselves to make the fact that there is someone who hates the very being less painful. That if you're racist you're probably some missing tooth ignorant hick and therefore you're socially below me and as a result I have a sense of superiority. You're setting yourself up to be sorely disappointed and eventually disillusioned if you have this view.
