His judgement is impaired, he is codependent on my mother, hasn't worked in years, and has a history of mental illness.
I don't think he is competent to handle tasks since my father's death several months ago. I've seen some bad judgement on his part and he encourages my mother's hostility against me. My mother is going downhill mentally and is turning against me for no reason.
Is there anything I can do to have him removed?
So, THEN, my question is: Why did both your mom and dad give your brother POA if he is, as you say, mentally disabled?
In my opinion, you'd have a real uphill battle to have him removed. Read money, expertt witnesses, atttorneys. Just because YOU don't think he's competent doesn't mean he isn't. That's the call of a medical professional. Without that, you're dead in the water.
I am really sorry that you feel mother is hostile toward you. Do you think it would help if you visit and never bring up the topic of POA or her codependency with brother?
Does your brother receive disability or does he live with your mother? If he lives with her, it would have been a good reason to appoint him POA. He could handle the bills easily and take care of things around the house.
I wondered what you would do about your brother if you were POA or guardian and your mother became incompetent. I have a feeling it would have been her wish to make sure he had enough. Mothers are like that.
"I am caring for my mother, living at home and the primary ailment is depression."
Are you caring for your mother living at home which I assume is yours or is your brother taking care of your mom whom he is living with in her home?
Is she on depression meds? Is she taking them?
Codependency is a two sided coin. If either side changes, the other side gets very angry. Codependent relationships tend to feed off of each other.
I don't like the idea that someone one disability and no longer works is by that alone not qualified to be a POA. I was on disability for years before, I needed to step in as my mother's POA. My very disabled step-dad would have let her die four years before she did had he been her POA. As her only child, I was both her medical and Durable POA. The largest burden I had to deal with was her several years of not filing her and her husband's taxes which she lied about them being done, but told the truth to her sister who did not think it was her place to tell me about years before when she knew that. Some people who are not on disability or not mentally ill aren't competent to be a POA either.
Perhaps the best thing you can do for your mother is cultivate a positive relationship with your unstable brother so that if he feels he needs assistance, he can rely on you to provide some guidance without being judgmental of him.
You don't have to approve of or support his lifestyle, just let him know in a supporting way that you'll be willing to offer advice and counsel if he faces having to use the proxy authority.