Donald Trump, in some respects, is best understood as an insult comedian; like Don Rickles, he says nasty things about his opponents, but in a way that permits him to argue that he doesn’t really mean it. He’s just joking. He shouldn’t be taken literally. That’s what his fans say, and a lot of people believe it.
But what works for Trump probably won’t work for Vance, or any other Republican. Vance tried to explain his “childless cat ladies” comment by saying it was just “sarcasm,” but the explanation isn’t working. Like most people, Vance has a history of meaning exactly what he says–at least until his interests cause him to change his mind–so nobody is going to accept that he is suddenly taking on Trump’s persona.
If Vance has any sense, he will learn to keep his mouth shut and his head down instead of inflaming the public discourse. That’s Trump’s job.