The Supreme Court has held in recent years that Congress is expected to be clear when it authorizes agencies to regulate issues of national significance.
[5] In a January 2022 decision regarding the authority of the Occupational Safety and Health Administration to require private-sector workers to be vaccinated, the Court reiterated that, “We expect Congress to speak clearly” if Congress wishes to empower executive branch agencies to make decisions “of vast economic and political significance.”[6][7] The Court arguably applied a similar approach in the 2006 case of Hamdan v.
[8][9] According to Professor John Yoo, the Court in that case attempted "to force a clear statement rule upon congressional delegations of authority to the President.
[16] In the 1987 case of South Dakota v. Dole,[17] the Court reaffirmed congressional authority to attach conditional strings to receipt of federal funds by state or local governments, but said there can be no surprises; Congress must enable the states "to exercise their choice knowingly, cognizant of the consequences of their participation."
Another area in which a clear statement rule operates is with regard to legislation potentially addressing the past, instead of being forward-looking as usual.
In many cases, the court has found "implied" prohibitions and causes of action in statutes, a result that would be precluded (or at least hampered) by clear statement rules.
Yes, the Supreme Court held in Gomez-Perez v. Potter, 128 S. Ct. 29 (2008) that a clear statement was unnecessary to prohibit retaliation of that kind.