The law is a completely valid exercise of Congress’ Commerce Clause power, and all the conservative longing for the good old days of the pre-New Deal courts won’t put us back in those days as if by magic. Nor does it amount to much of an argument.If you look at the legal precedents, the case for the constitutionality of the Affordable Care Act is close to open-and-shut. The idea that the ACA's regulation of the "inactivity" is a novel and unconstitutional use of the federal government's power under the Commerce Clause doesn't really pass the smell test. But when has that stopped the courts conservative Justices when they really wanted to do something? The Justices and Court clerks have tremendous ability to use the tools of legal reasoning to achieve a desired result; they just choose to exercise that ability sparingly. You see their talents on display most clearly in the abortion cases that have reached the post-O'Connor Court, but arguably one can see it in Parents Involved and other contentious decisions. And the stakes here are high enough that the Justices will almost certainly be influenced by the political atmosphere surrounding the case.
So that brings us to the really interesting question: Will the Court’s five conservatives strike it down regardless?
Another way to put this is that after Bush v. Gore, I'll believe anything.