Abuse.
Religion usually plays a part.
Accepting the fundamental differences in viewpoint and pretending it isn’t there for the sake of kids
Etc.
My partners family comes to mind. Her mother is very liberal, her dad is a weird mix of liberal beliefs polluted by religion. They just don’t talk about it, everyone knows he’s wrong, he knows he’s wrong, he won’t change his viewpoints and his wife isn’t willing to collapse their family over it.
Thanks saved me the watch