Such places have done exactly that, in several ways. E.g.: https://en.wikipedia.org/wiki/Redlining
This a good source of tens of other methods (and it's not even up to day) used in L.A in general to keep the "riffraff" out:
>Beverly Hills residents were among Barack Obama's most generous donors.
That's not really relevant. They can virtue signal how non-racist they are (as long as it doesn't cost them anything real -- donations help buy favors) and still only live in 99% white areas, with closed gates, and local pops/private police ready to harass black/latino people for your protection.
>You think they would stand for that kind of evil in their own city?
You're not presenting evidence specific to Beverly Hills here. Saying that "such places have done exactly that" is not evidence of what's happening today specifically in Beverly Hills. And redlining is not a scheme for harassing people who are walking around on the street. Why is that your response in this context?
> They can virtue signal how non-racist they are (as long as it doesn't cost them anything real -- donations help buy favors) and still only live in 99% white areas
You're assuming the very point you should be proving. You haven't offered any evidence about why some BH residents supported Obama. Instead, you assigned them a motive without providing any objective evidence. How are you going to persuade anyone of your viewpoints that way? And Beverly Hills is not 99% white.