The only "unchosing" I can think of was with a college roommate and very good friend who at the wise age of 18 (this was the late '70s) decided to become a full-fledged vegan. It was a political statement that it was morally wrong to exploit animals for our own existence. She had many other rationalizations (environmental, health) to justify it. The idiot has stubbornly hewed to it well into her 50s, with elaborately self-deceptive rationale.
When I saw her subject her own baby to it, her own little kid, poor starving little monkey -- he clung to her like a skinny little monkey with bleary eyes -- I had to turn away. I unchose her, and it was mutual. She had to know I'd lost all respect for her. When someone tells me they are vegan, even when they're young, they drop about five notches in my book.
Those relatives must have some loud politics for you to unchose 'em!
It's just ground in leftist indoctrination that's now too deeply embedded to extract.
They bought in at an early age, and gradually surrendered all personal responsibility and self determined ability to analyze, to a rigid dogma that requires a sort of religious faith to hold it in place.
There's no profit in trying to talk to them about politics or culture in general, unless you parrot Communist thoughts that interlock with their faux reality receptors.
You may as well be asking them to give up their god. It's a system of belief, and no amount of logic, reason, or facts are going to penetrate their minds. I don't believe as they do, therefore I've gone to the 'dark side'. It's no more complicated than that.
I've had to completely sever ties with the most ardent 'true believers' in my family. They're literally insane.
The American people still believe in vegans even if they are not one themselves.