Bills of Attainder: The Constitutional Implications of Congress Legislating Narrowly [August 26, 2014] [open pdf - 253KB]
"On occasion, Congress exercises its legislative authority regarding a specified individual, entity, or identifiable group in such a way as to raise constitutional concerns. In particular, the United States Constitution expressly prohibits the federal government from enacting bills of attainder, defined by the Supreme Court as a 'law that legislatively determines guilt and inflicts punishment upon an identifiable individual without provision of the protections of a judicial trial.' The basis for the prohibition arises from the separation of powers concern that the enforcement of a bill of attainder would allow Congress to usurp the power of the judicial branch. For instance, in recent years, Congress proposed retroactive taxation of up to 90% of the value of bonuses paid to employees when an employer had received funds from Troubled Asset Relief Program (TARP). [...] The Court has suggested that each bill of attainder case turns on its own highly particularized facts, and notably, since the signing of the Constitution, the Bill of Attainder Clause has been successfully invoked only five times in the Supreme Court. Nevertheless, there remain potential constitutional concerns when Congress proposes or passes legislation that imposes a burden on a specified individual, entity, or identifiable group."
CRS Report for Congress, R40826