It's an interesting point. If they are ignorant (perhaps without the wilful), then perhaps when you present them with facts and information, they might change

It's an interesting point. If they are ignorant (perhaps without the wilful), then perhaps when you present them with facts and information, they might change their mind. If they are malicious, they won't change their mind in the face of any facts or information, because their motivations are underhand and cannot be reasoned with. I suspect in cases like this it's probably a bit of both (and perhaps in the case of this particular MP, she might just be toeing the party line).