I think you got it backwards. Most - damn near all - people are completely unaware of their bias. A few people, such as yourself, are aware of it.
It is possible to change. I dislike Trump. I've always disliked him, from way back - long before he started dabbling in politics. So when he first got into the game everything he said would have me rolling my eyes. I've slowly moved away from this attitude - thanks in full to the petulant hubris of the left in general, and the media specifically. Their blatant attitude of "Anyone in their right mind would agree with me" disgusts me so deeply that it is palpable. The media's blatant misrepresentation of everything Trump says and does - along with the rabid pursuit of issues which should just fade away, and the mob's reaction to what they're fed by these a-holes, physically sickens me. I find the very existence of Antifa offensive - and you have to work hard to offend me.
And, frankly, I'm somewhat amused watching the Streisand/Cobra/Blowback Effect(s) that they're making happen. For instance, I now give Trump way more of the benefit of doubt than I think he actually deserves. I am keenly aware of my bias, and I'm disciplined enough to stop it, however, I am not inclined to do so at this point, because of the above. I rather think it's possible that by the time the next election rolls around I'll be a staunch Trump supporter. Out of pure spite.
Anyway, back to your point - I honestly believe that most people are so self-unaware that, not only are they oblivious of their bias, but they will actively deny they have one, and will argue and/or fight with you to prove it.
