There is a class of people, who vote, to whom fact-checking isn't a part of their day to day life.

That is not at all true. You just don't value or respect their style of fact-checking. If they see it on Fox News it must be real. If they hear about it on Info Wars it must be real. If it shows up in their Facebook feed it must be real. If they hear it from a friend it must be real. But if it gets forwarded to them from Mother Jones? They're going to ignore it because it's fake news.

There's that nasty, five dollar word "provenance" again. There is no one walking this earth that credulously accepts what their eyes see and their ears hear when it disrupts their worldview. That's the core of the issue: who do you trust and why do you trust them. Twenty years ago nobody said "it's fake I can tell from the pixels" but now 70-year-old women have an opinion about Photoshop.

I am making the point that it is even more easily dismissed in the era of deepfakes.

But it's not. It was sourced from a known recording at a known event whose provenance was confirmed by those responsible, and then disseminated via a major entertainment source on a national broadcast network. Sure - trip across it on 4Chan and you doubt it.

And the forgery of imagery, no matter how compelling, has always been a matter for amateurs.