Skadden, Arps, Slate, Meagher & Flom, LLP v. Michigan Department of Treasury

(1) Whether a state statute that retroactively imposes over $1 billion in increased tax liability on out-of-state businesses for the benefit of in-state businesses violates the dormant commerce clause; (2) whether a state tax law that has a 6 1/2-year period of retroactivity and targets out-of-state businesses for increased tax liability of over $1 billion violates the due process clause; and (3) whether a state's retroactive repeal of a central provision of the decades-old Multistate Tax Compact violates the contracts clause by imposing over $1 billion in retroactive tax liability on out-of-state taxpayers.