AI voice synthesis is getting good https://m.youtube.com/watch?v=-9Ado8D3A-w&feature=youtu.be

Will someone use this technology to create a fake recording of a politician saying something inflammatory, where the opposing party then points to this audio as supposed evidence of wrongdoing?

For this market to resolve Yes, one party (or some extension of the party, such as a politically-aligned news organization) must attempt to use the fabricated audio to damage the opponent's political prospects. It is not sufficient for the audio to simply exist. For example the USPresidentsPlay youtube series would not count because no one is treating the audio as credible.