JONATHAN ADLER: The Sackett Oral Argument and the Problem of Defining “Waters of the United States: The justices wrestled with the problem of identifying a clear, coherent, and administrable definition to constrain federal regulatory jurisdiction under the Clean Water Act.”

If you can’t clearly define a federal power, then it should not exist until you can. One of the bedrock principles of our constitution is supposed to be that federal powers are limited and defined. If you can’t limit it and define it, it’s not a federal power. (Note: My opinion not necessarily that of the Supreme Court.)