“I’ve encountered the same from groups of blacks in various places. It’s my cue to give them a wide berth.”
This atmosphere is toxic; most people (rightly) avoid going anywhere they get that hateful glare. De facto segregation; my leisure time is rarely spent anywhere the “glarers” go...
In 1981 I joined my classmates from the Bell System Center for Technical Excellence (Lisle, IL) on a weekend trip to "Great America" in Wisconsin. We were living in the school accomodations for 15 weeks of intense training. Getting out for the weekend was a relief...or so we thought. Once inside the park, we found ourselves waiting in line with large groups of aggressive (physically and verbally) blacks. Geez...the blacks in San Diego aren't anywhere near that nasty. It was a trip spoiler. We left early. Never again.