What rights do I have to guardianship over my father?

My father re-married after my mother''s death. It has been a rocky relationship since then. He has ended contact with me, although I have tried and tried to make-up. His new wife wants nothing to do with me, and told me that everything was hers now. She has my mother''s belongings and controls my Dad. He now has Alzheimer''s Disease. Do I have a legal right to know how he is doing and what care he is getting? Do I have a legal right to demand that I get to see him? He lives in New Mexico, and I live in Indiana. I used to have power-of-attorney, etc, but he removed me after my mother''s death. I think his new wife or family probably has it. I''m pretty sure that he has removed me from his will by now, and that I am probably not a beneficiary on his IRAs anymore.