I have seen this come up each time Intrade comes up and it doesn't make sense to me. It was struck down as unconstitutional. It was changed to a tax and then upheld.
It was not struck down as unconstitutional. It was upheld as constitutional. The Court said congress did not have authority under the commerce clause to force people to buy insurance, but did have the power under the taxing clause to impose a penalty upon them for failure to do so.
Anyway, the purpose of my post was not to argue the merits of the Obamacare decision, but to illustrate as others have said that Intrade is not a good indicator of outcomes.
Your picking nits.