The concept of legislative purpose fascinates me. Specifically, how, and when does the Supreme Court sniff out Congressional purpose? A few primary areas are:

• in dormant commerce clause cases, where the court sniffs out “protectionist effects”
• in equal protection cases, where the court sniffs out “invidious purposes”
• in establishment cases, where the court sniffs out a “secular purpose” (I have written a bit about this last one in This Lemon Comes as a Lemon. The Lemon Test and the Pursuit of a Statute’s Secular Purpose)

In some future article, I want to compare how the Court finds intent in these different cases, and perhaps theorize why different approaches are used for different areas of the law.

Professor Pursley has posted a new article to SSRN, titled Preemption in Congress (H/T Legal Theory Blog) that considers one other area where the Court considers purpose; intent in Preemption.

Judicial treatment of the authorization question is confused and confusing. In applying
a rule that congressional intent is determinative of the existence and scope of preemption;
courts appear to assume that Congress is always and already authorized to preempt state law.

But how is this “intent” determined for pre-emption purposes? As the Court wrote in Jones v. Rath Packing Co., 430 U.S. 519, 525 (1977), “Congressional intent to preempt “may be explicitly stated in the statute’s language.” See, e.g., Lorillard Tobacco Co. v. Reilly, 533 U.S. 525, 541–48 (2001); Shaw v. Delta Air Lines, Inc., 463 U.S. 85, 95–98 (1983).

How does pre-emption intent differ from dormant commerce clause, equal protection, and establishment clause cases? And why would the Court take different tacts.

No answer now, but I will consider this going forward.