… is from page 260 of Randy Barnett’s important and learned 2004 volume, Restoring the Lost Constitution: The Presumption of Liberty; Randy here refers to the Necessary and Proper Clause of Article 1, Section 8 of the U.S. Constitution – a clause that requires all Congressional legislation to be both necessary and proper to carry out the enumerated powers delegated in Art. 1, Sec. 8 to the national government:
The original justification of the presumption of constitutionality [by courts in the U.S. of legislation] rested, in part, on the belief that legislatures would consider carefully, accurately, and in good faith the constitutional protections of liberty before infringing it. This belief assumed that legislatures really do assess the necessity and propriety of laws before enacting them. In recent decades, however, we have remembered the problem of faction that (at least some of) the framers never forgot. We now understand much better (or are more willing to admit) than our post-New Deal predecessors on the left and on the right that both minorities and majorities can successfully assert their interests in the legislative process to gain enactments that serve their own interests rather than being necessary and proper.