I don't see how the bill being thrown out would lead to anything other then a freefall in Obama's approvals... his signature achievement thrown out would be the theme kicking off every nightly news across America
Well, two points (1) it would be rightly seen as the fault of the Supreme Court. Even those who oppose the law admit that it being thrown out was highly unlikely in early 2010. No one could have been expected to foresee such activism. (2), Obama's approvals aren't based on "his signature achievement." They're based on the fact that he's a Democrat, the state of the economy, and his personal character. Obamacare being thrown out wouldn't lead his support to collapse. Only if he betrayed his party in some fundamental way (nearly impossible), the economy crashed into a depression, or a Edwards/Nixon-style personal scandal would do that. But yeah the negative news coverage would probably hurt his ratings.