So, how do you deal with people who " blame"..
1) talk to the person, ask them why they feel others are to blame in specific situations, consider their answer. Is there ANY truth to how they see the situation? Believe in your instinct and common sense and ask yourself if you are really to blame in a situation where you are being blamed.
2)Let them know how it made you feel, when they blamed you for something that you felt was not your fault or was out of your control, avoid whether they were "right" or "wrong" as that is only your opinion and it will be a very difficult battle to "win".
3) Have a good sense of yourself and how you feel. Remember that if you can see the behavior as anti social, others will as well.
You do not need to be the enforcer, sometimes the best course of action is to simply remove yourself from the situation and leave the affected parties to fight their own battles. Blamers can have a negative effect on the people around them, but their true power comes from the people who allow them to disrupt and influence their lives.
4) Consider putting extra distance between you and the blamer, you can not force change on others, but you can change yourself. Relationships of this nature are often just a one-way street where you put a lot into it but the reciprocal feeling is only an illusion.
Seek relationships with people who believe in you and support your ambitions.