I also didn't find the videos hard, as lip movement looked quite fake. Maybe for some people they would fit better, but both Trump and Biden are too old to move their lips so vigorously.
As for the text: you can easily have more than 50% success rate:
- with political knowledge you know some things are unlikely to be said by a given politician
- ironically, if the text is grammatically correct, it's unlikely that it was actually spoken by a politician - real transcripts have stuttering. Of course AI could be train to contain stuttering as well, or a bad AI could spew out complete garbage. I think in case of both Biden and Trump that makes it especially hard to differentiate between bad AI and them :D.
Even a genuine quote can be presented out of context.
For an example that is a bit on the nose, I recently read a quote from Sebastian Haffner about German history, that went like this:
> Germany was a much happier place at the turn of the 20th century than it was in the 80s.
Which sounds odd, coming from a left-wing, liberal journalist - unless you know from context that he was talking about the 1880s, not the 1980s. He was not wishing the Kaiserreich back, he was just comparing different historical phases of it. Nevertheless, without the context, the quote would look highly strange, even if it is technically not a fake.
As for the text: you can easily have more than 50% success rate:
- with political knowledge you know some things are unlikely to be said by a given politician
- ironically, if the text is grammatically correct, it's unlikely that it was actually spoken by a politician - real transcripts have stuttering. Of course AI could be train to contain stuttering as well, or a bad AI could spew out complete garbage. I think in case of both Biden and Trump that makes it especially hard to differentiate between bad AI and them :D.