This case presents an issue regarding the constitutionality of retroactive taxes. In December 1987, to correct a drafting oversight, Congress retroactively amended the requirements of a federal estate tax deduction enacted in October 1986. The Ninth Circuit, using a lenient test, invalidated the amendment’s retroactive application to a December 1986 transaction. Now the case is before the Supreme Court whose decision should indicate whether the Court will relax the almost overwhelming barriers to a successful attack on retroactive taxation established by its earlier cases.