She’s your mom. There’s nothing you can do about it. Certainly try to influence her if you can, but it sounds as though you can’t. So whatever. Live a happy life, vote right, influence the people that you can.
My Dad is 100 yrs old and a yellow dog democrat. I think he’s entitled to vote for who he wants. I love him. He is my Daddy and he is from a different generation. I vouch that he is neither senile or stupid and he has plenty of money because he worked until he was 70 yrs old laying pipeline for an oil company. He is the most moral and christian man I have ever known.