One way to look at the possible effects of deepfakes in politics is to look at "shallow fakes" that have been possible for a long time.

For example, this screenshot purporting to be a "you're free to say whatever nasty stuff you want" whitelist for twitter. I actually have no idea if this is real or fake, but there definitely are some people who are treating it as real, imo without sufficient evidence. And yet, the effects of things like this are pretty bounded.

This feels like a plausible outcome for deepfakes in politics. The smart people know not to trust a politician's statements without confirmation on official channels, and less smart people get tricked, as they do today with shallow fakes. If something fake goes viral, Community Notes can help on the margin in making it clear that it's fake. Most normies don't actually look at this stuff in real time, and so the effect ends up not too bad. This is the strongest case for not being too worried.

The place where I am *more* worried about deepfakes is...

Fakes, whether deep or shallow, are ‘bottom-up’ and to your point fragile in the face of collective intelligence.

The real threats are top-down, like editorial bias by authoritative sources.