Is the DJA's tax exception "jurisdictional"—and, if so, does it bar a case that is not barred by the AIA? That is, in a case between two private parties that does not involve the assessment or collection of any tax—and where the Petitioner's primary purpose is to recover her own property—does the DJA's federal-tax exception deny subject-matter jurisdiction to declare the owner of a brokerage account, even though the AIA is not a bar? And if so, does the fact that Congress has not provided Petitioner with an alternative legal forum to resolve the ownership of the account give rise to an exception under this Court's decision in South Carolina v. Regan, 465 U.S. 367 (1984)?

Is the DJA's tax exception barred by the AIA?