The main problem is people, not stuff.
http://www.npr.org/templates/story/story.php?storyId=122864641 points towards the problem. It's not "racism," racism is just a particular kind of tribalism.
The problem is complexity. Another thread asks why, when there's so much information available people are so stupid. After all, anybody could research the HCR and come to the same conclusion as that poster. Perhaps, but to really look at all the info would require reading the Senate's and House's HCR bill, Obama's pronouncements, and then punditry, relative statutes, regulations, and case law to figure exactly what the law means, and then a fair amount of economic and social theory to figure out whether the prediction are reasonable and come up with one's own predictions. Stupid is easy. Having something akin to an opinion is easy. Being well informed? Not so easy.
It's the same with experts, with critical thinking, with US politics. It's too complex to get your mind around. You can't think critically without facts, you can't trust experts unless you evaluate their claims and for that you need facts and critical thinking, plus more information than you can process in a given week.
Same for social groups. We can handle groups up to a certain size, depending on how cohesive they are. The less cohesive, the small they have to be. Having outside threats helps instill cohesion, real or imagined. Kids (per NPR per the book cited) have to categorize. The world is too complex without it. That person next door: I have to decide how much to trust him. And the one beside him, across the street, around the block; the kids on my kid's schoolbus; the teachers and administrators, and people in restaurants, on the street, and on those rare occasions I'm in a mall. So I have a certain level of trust and good will, and how do I parcel it out? I can use race, I can use class, I can use accent, I can use ideology, I can use citizenship, I can use language or accent, or dress or some other proxy. But I will use something. Then I'm in a group, and as a primate will seek to help my group, those I empathize with and find support from. That means I'll sacrifice perks for other groups. I'll complain bitterly when others sacrifice my perks for their own good, or when they sacrifice perks for groups I'm sort of in for groups I'm not in and don't expect or want to be in.
From that, violence of one kind or another. Remove that, all wars are accidents--but then only possible if there's no enough good will.
There are kludges. Find a more inclusive proxy, like the US and nation-states did. Islam's serving as a proxy for many. Remake human nature so we stop striving for more, so we honestly don't care about the perquisites of group membership.
As for whether that'll help the species survive in the long run or not, can't know. So that may be an evolutionary mis-step. Or not.