The latter example is easily taken care of though, because there has to be a market to take your bet if the market has no reason to believe you would win your o

The latter example is easily taken care of though, because there has to be a market to take your bet if the market has no reason to believe you would win your odds are really low thus your winnings over your billion are really low. On top of that your risk is not symmetric as you've exposed your self for some to now spend what millions to campaign for you and thus bet against that pool. My point is your example is contrived and not really useful.