Adam Serwer has done excellent blogging on the court challenges to the Affordable Care Act, and I recommend you read it all, but I wanted to highlight this particular point:
My personal belief is that Republicans hate the law and want to see it gone, and so the conservative justices on the court, with the possible exception of Anthony Kennedy, will happily oblige them. The justices' identities are simply more partisan than we acknowledge -- does anyone remember Scalia decrying the 17th Amendment before it became a Tea Party cause?
Public discussions about the Supreme Court would be a lot better off if we all just dispensed with the fantasy that the Constitution has anything (or much) to do with Court decisions. Granted, it does in some cases -- usually those on the margins -- but for issues that fall within the public discussion, you can reliably assume that Justices will follow the path of public opinion and ideological preference. In other words, the Affordable Care Act will be safe for as long as the public finds it broadly acceptable.
Relatedly, if the courts are just another stage for political and cultural fights, then liberals would do themselves a favor by refocusing their efforts on the judiciary, and in particular, pressuring Democrats to nominate and confirm judges who fit broadly within mainstream liberalism.
-- Jamelle Bouie