This is about DHH, but I found this to be the best explanation of dogwhistling in general:
He [DHH] skirts right up to the edge. When he says that it’s grotesque that other people are prevented from advocating that I should be physically assaulted – he’s made it loud and clear to me that he hates me, that he doesn’t want me to exist. Other people can’t hear it. That’s a dog whistle.
Ask a random bystander to adjudicate this and I’m in trouble.
That bystander will find this to be impenetrable. It takes forever to explain. David can bat his eyelashes, and say he’s just raising “reasonable” concerns. In the end I’d be asking this bystander to decide who deserves more benefit of the doubt: is it the rich, charismatic, famous guy or the histrionic, weirdo, gender deviant?25
He has a lot of social credibility, and he exploits that fact.
He has never had social credibility with me, so I sometimes forget that he does have a lot of social credibility. It’s a lot of power, albeit with a relative niche. People loved that guy the way they love other smart-esque didactic assholes like Steve Jobs.
Imagine if Jobs had used his credibility to move against immigrants the way he did against Flash? Developers would be flooding the App Store with ICE collaboration apps.