That is human nature, though.
Everyone sees it that way - It's how we instinctively tell friend from foe.
Like Us vs Not Like Us.
It exists everywhere someone has something about them that distinguishes them from others, be it skin colour, physical build, choice of music, football shirt, hairstyle, wealth or even choice of motorcycle.
I thought that when we voted for Tony (or not, as the case is), the idea was that Brown is the back-up that's supposed to step in if Tony leaves? We vote for the party and the leader gets the PM role? His second takes over if neccesary.
Everything else.
Oil, land, crops, marriage, racial supremacy, freedom, slavery......
Personally, I'd rather be fighting aliens, but that's just because I want a Pulse Rifle!!