I agree with the former, and conceptually with latter. But we've seen people vote against their best interests because of the promise of destroying those who've they've been taught to hate. Contemporary US immigration "policy" is a case in point.

No, we haven't. People do not "vote against their interests", as much as commenters online love to claim that. What actually happens is that they believe what they vote for will advance their well-being, and you disagree with their assessment. That's a very, very different thing.

The idea that there are any significant number of people out there deliberately hurting themselves for hate's sake is a complete myth. People reach for it because it feels good to imagine that your opponents are hate-warped idiots, but there is not a shred of evidence to support such a claim. When you actually talk to people (and not just assume you know what's in their heads), you find out that they, like you, are just trying to do good in an imperfect world.