My guess is that the mandate is upheld. Kagan, Breyer, Sotomayor and Ginsburg are likely to uphold while Thomas and Alito are likely to rule that the Commerce Clause doesn't provide a Constitutional basis for the Mandate. That leaves Roberts, Scalia and Kennedy. Many feel that Kennedy could be the deciding vote, but I believe that Roberts will also vote to uphold the Mandate. It should be noted that Scalia has previously taken expansive views on the application of the commerce clause.

While we all tend to look at this as a political football in an election year, the Justices, believe it or not, have to reconcile their decisions, based upon the principles of stare decisis, and the language from their own relevant decisions. Scalia likes to be conservative, but he likes even more to be consistent in his decisions.