It's premature to assume that the tough questioning by US Supreme Court justices will translate into a ruling that the Obamacare "individual mandate" is unconstitutional.
For what it's worth, the prediction markets at Intrade suggest a 60% chance of a negative outcome for the Obama administration (price at time of drafting this post).
What is perhaps more interesting, and will fuel conspiracy theories, is the effect on President Obama's re-election chances. They're creeping up (heading towards the 60% mark). Some people seem to think that if the Republicans win both the Senate and the House of Representatives this will ensure less public spending and borrowing, but with Obamacare out, or at least reformed, the suggestion is that President Obama can be like Bill Clinton's second term.
Is it possible that the hesitant performance of the Solicitor General, Donald Verrilli, and the sharp questions from Obama-nominated supreme court Justice Sotomayor, are the visible part of a strategy of dumping policy for a November presidential win?
I don't think this will work, unless there is either an economic recovery or some reason to believe that it is on the way. But it could defuse the biggest motivator for the Tea Party movement. And the Supreme Court can take the blame with Democrat voters...
Any offer of 40% or lower for a Republican presidential win seems generous at this stage.
UPDATE: The LA Times' Politics Now blog seems quite certain the whole Obamacare legislation is going to fall.