While I'm not going to say "There's nothing to that.", This quote from that article points to that there might be some "Big Picture" stuff to also take into account...
Folks with Parkinsons' related dementia often think someone is trying to do something bad to them. I think that it could have something to do with that in addition to playing into what you mentioned.“A lot of research shows that older adults suffer losses in their ability to inhibit unwanted thoughts,” Von Hippel writes me in an email. “We have found that older adults who try to prevent stereotypes from influencing their judgment typically find that they rely on them more and more as they age. … Aging will tend to make many people more negatively disposed toward immigration.”