Yes, Tradesports can be sold short, I believe. But that doesn't affect the theoretical validity of Tradesports; someone being certain a candidate will NOT be chosen is as indicative as other being certain that candidate WILL be chosen... Or are you speculating that maybe someone is trying to purposely drive down the price of Luttig?
Well, like any market, this would appear to be vulnerable to manipulation by a deep pocket, especially if shorts are present. In this case though, the risk is finite since the max value is 1.00 so maybe just your normal whipsaw manipulation would be present.