It sounds to me like you have made a very good start. What an amazing position you find yourself in.

You can not tell them how to think, but you can get them to think about what they say.

Can you ask them if they believe the government should fix "problems" like racism and unequal rights for homosexual individuals?

Can you ask them if they think Barak Obama is not an American in the way a "Roma is not a Bulgarian."  How do they see that difference?

Can they tell you what it would mean if a blonde American born woman chose to stay in Bulgaria and "become a citizen?" Would a theoretical  "white Bulgarian born" child of yours be Bulgarian?