You recall this from last year's Violence Against Women Act case, but it's still worth a footnote. Under Article 1, Section 8 of the federal Constitution, Congress cannot regulate anything unless it implicates interstate commerce. Part of the fun of the last hundred years has been the courts' and Congress' expansion of what comes under the umbrella of interstate commerce. Still, in two 5-4 decisions over the last five years, the Rehnquist Court has refused to define guns or violence against women as implicating interstate commerce.