I wonder how much of a deal breaker his lack of charisma is. Certainly people have been elected without it, but it's a nice equalizer if you're short in other areas, like experience.
Either Trump's lack of experience will prove to be a huge negative and hurt Zuckerberg due to his similar lack of experience, OR Trump will somehow turn things around and be successful enough to be competitive in 2020 and Trump can claim he has more experience.