Useful example is how the Joe Biden Burisma phone call that bubbled up through Russian media was fabricated. I pulled it apart with ffmpeg and there were a number of artifacts that showed editing and splicing.

If you're handy with ffmpeg and python, you can assess their veracity pretty easily. Of course, if I were on a political ratf'ing team, I'd use the same tools to add those artifacts to a copy of an offending (real but off message) stream and amplify the distribution of that fake-faked version with a debunking press release handy, so YMMV. While the Biden thing wasn't a deepfake directly, (shallow fake?) we're going to see tons of actual deepfakes around the election.

IMO, elections are no longer between candidates, they are a war on truth for domination of the narrative - office is the effect. A campaign that focuses on what happens once the war is over is daydreaming about the future and distracted from the present and this will lose them key battles. For this reason, I think deepfakes are going to be the biggest weapon in campaign arsenals for the near future. Interesting times.