Childlessness is a very bizarre topic to make the centerpiece of one's political philosophy.
As another pointed out, Vance is calling "sociopathic" the entire infrastructure of Catholicism, from Pope to priest.
Indeed, one might mention to him that Jesus and his disciples were childless, not to mention not even married.
Or, if one prefers a more "scientific" argument, Vance is out of his mind, insane, and.... WEIRD.
Politically, can Vance be so ignorant, so out of touch with reality, that he cannot grasp that not having children by choice or circumstances isn't a partisan political issue? That there are child-free Republicans?
That probably the majority of gay couples have no children? That young voters still in college probably don't have children, for the most part?
And do parents whose children have passed away still get to vote? Do grandparents get to count their adult children?
That the bee in Vance's personal and political bonnet is that "an absence of children is the definition of having no stake in the future" shows quite the paucity of intelligence, of imagination, of even relating to being human.
That he can see no reason other than having offspring to be concerned about the environment, climate change, public education, democracy itself, shows a mind bereft of a modicum of intellectual maturity.
That is all to say, JD Vance thinks as a two-year-old.
And perhaps such stuntedness is a psychological defense mechanism, IYKWIMAITYD.