A district court judge in Virginia ruled in December that the individual mandate in the national health care law is unconstitutional. Despite the lack of a "severability clause," that judge ruled that the rest of Obamacare was constitutional (whether or not Obamacare would be functional without the mandate is another question).

Now a district court judge in Florida named Roger Vinson has ruled that the individual mandate is unconstitutional, and thus so is the entire law. Here's Vinson on why the entire act is unconstitutional if one part of it is unconstitutional:

First, the Act does not contain a “severability clause,” which is commonly included in legislation to provide that if any part or provision is held invalid, then the rest of the statute will not be affected. Although it is true that the absence of such a clause, in and of itself, “does not raise a presumption against severability,” [New York, supra, 505 U.S. at 186], that is not the same thing as saying that its absence is irrelevant to the analysis. In INS v. Chadha, 462 U.S. 919, 103 S. Ct. 2764, 77 L. Ed. 2d 317 (1983), for example, the Supreme Court concluded that it did not have to embark on the “elusive inquiry” of whether Congress intended the unconstitutional provision in that case to be severable from the rest of the statute because Congress included a severability clause with language that was plain and unambiguous. See id. at 931-32. And, in Alaska Airlines, Inc., supra, 480 U.S. at 686, the Court similarly held that the severability analysis is “eased” when there is a severability clause in the statute, such that only “strong evidence” can overcome it. By necessary implication, the evidence against severability need not be as strong to overcome the general presumption when there is no such clause.   The lack of a severability clause in this case is significant because one had been included in an earlier version of the Act, but it was removed in the bill that subsequently became law. “Where Congress includes [particular] language in an earlier version of a bill but deletes it prior to enactment, it may be presumed that the [omitted provision] was not intended.” Russello v. United States, 464 U.S. 16, 23-24, 104 S. Ct. 296, 78 L. Ed. 2d 17 (1983). In other words, the severability clause was intentionally left out of the Act. The absence of a severability clause is further significant because the individual mandate was controversial all during the progress of the legislation and Congress was undoubtedly well aware that legal challenges were coming. Indeed, as noted earlier, even before the Act became law, several states had passed statutes declaring the individual mandate unconstitutional and purporting to exempt their residents from it; and Congress’ own attorneys in the CRS had basically advised that the challenges might well have legal merit as it was “unclear” if the individual mandate had “solid constitutional foundation.” See CRS Analysis, supra, at 3. In light of the foregoing, Congress’ failure to include a severability clause in the Act (or, more accurately, its decision to not include one that had been included earlier) can be viewed as strong evidence that Congress recognized the Act could not operate as intended without the individual mandate.

Allahpundit notes that a Democratic aide said the omission of the severability clause was just an "oversight."