I don't know enough about the inner workings of the Supreme Court to give an educated answer, but while listening to Rush talk about Kagan and the Obamacare arguments I wondered if there was still an opportunity for her to back out of the case. Given that she designed the legal defense for Obamacare she clearly had no business being part of this case.
Let's say for instance she decided not to recuse herself initially because the administration was so concerned that they'd need her vote. At some point in the near future the justices will gather around their conference table and cast the actual votes that will decide the various cases before them. The opinions will be assigned and the deliberation process will effective be over. If there's a 5-4 (or more) to overturn the mandate and all of Obamacare Kagan's vote will no longer matter. I wonder if she might be able to recuse herself at that point in order to try and retain some semblance of integrity?
Just a thought. Anyone out there who knows more about the court than me feel free to chime in.