alt Hacker NewsYes but in this case, tens or hundreds of people know the outcome months in advance. I'm very surprised that the market doesn't immediately converge to 100% for one candidate. The winner is not really a forecastable 'random event' in that by the time the show is airing, it's not being pulled from a distribution.
In theory, an insider willing to take any positive-expectation bet would drive the market price arbitrary close to the correct answer, but in practice they might be under NDA and want to avoid getting caught, or they limit their bet amount for other reasons, so the market ends up dominated by gamblers placing uninformed bets.