Yikes... Did you actually read what I wrote? Or the study? You're completely misinterpreting it. It's not saying that "everyone belongs to a genetically determined race", it's simply saying (duh) that these genetic clusters can be measured, and it shows some relationships between them that might be indicators for recent shared ancestry, etc...
This is specifically a chart of individuals with "pure" ancestry. People with mixed ancestry (i.e. almost all of us) have no spot on it. It doesn't tell us anything about our "race".
To get back to the example. If "blacks" belong on the bottom left than Obama (with his northern european mother) isn't black. So either he has a "race" or he doesn't. Which is it?
Stop thinking about "race" as a measurable thing, it isn't.
There are clear, genetic clusters corresponding with what we generally call races.
The fact that some people, mostly from the former European colonies, won't perfectly fit doesn't change that. The fact that this distinction is blurred, emphasized, or altered for political reasons doesn't change that. The fact that outward features, which are often used as proxy for the underlying genetics, can sometimes be misleading doesn't change that.
Also, I don't think "almost all of us" or even most of us wouldn't fit into those clusters. Do you have a source?
I understand that Obama is not exactly technically black; that legal, political or self-identified race may not align with those clusters or even known ancestry but it doesn't invalidate the concept. Just like there are people who are legally blind, and a subgroup who really can't see anything.
In the cluster on the left.