I'm not familiar with the difference between Do(Elect Clinton) and (Clinton Elected). Looking at the numbers, it seems that the first one is "Clinton is elected, either because that was going to happen anyway or because of an intervention", and the second one is "there was no intervention, and Clinton was elected"? (Or if there was an intervention, it was an unnecessary pro-Clinton one.)

I understood it like this: there is a group of people who will commit to changing the election somehow iff the prediction market says it would be good. If the market is neutral, then whoever gets more votes will win.