On the flip side, the video could be 100% real, showing a politician (or criminal) engaging in unsavory or illegal behavior, and they can claim it's AI generated and people will believe them. It will change everything.
They will all have watermarks to prove they are fake or real, but that will all be lost to viewers due to the low information voters not caring to be concerned about it, and the technology companies doing strategic silence to suit their agendas.