A group of five legal experts filed an amicus brief on Thursday in the case of Texas v. United States, which concerns the constitutionality of the Affordable Care Act absent the tax penalty associated with the individual mandate. The plaintiff's case in Texas rests on the argument that the ACA is "inseverable" from the mandate, the mandate is unconstitutional without an associated tax penalty, and that the entire ACA is thus also unconstitutional.
The brief staunchly opposes this severability argument (which was recently supported, in part, by the Department of Justice under President Donald Trump):
The cornerstone of severability doctrine is congressional intent. Under current Supreme Court doctrine, a court must offer its best guess on what Congress would have wanted for the rest of the statute if a single provision is rendered unenforceable. But this guessing-game inquiry does not come into play where, as here, Congress itself has essentially eliminated the provision in question and left the rest of a statute standing. In such cases, congressional intent is clear—it is embodied in the text and substance of the statutory amendment itself. Under these circumstances, a court's substitution of its own judgment for that of Congress would be an unlawful usurpation of congressional power and violate basic black-letter principles of severability.
The group of legal experts—Jonathan H. Adler, Nicholas Bagley, Abbe R. Gluck, Ilya Somin, and Kevin C. Walsh—includes both fierce advocates of the ACA and fierce opponents. Adler filed briefs against the ACA in the King v. Burwell case, while both Bagley and Gluck filed briefs in defense of the law.