In today’s decision in Hein v. Freedom from Religion Foundation, a decision on taxpayer standing to challenge potential violations of the Establishment Clause, the Justices come up with three answers to this question: 1) Read it narrowly (Alito, Roberts, Kennedy), 2) Overrule it (Scalia, Thomas), 3) Read it broadly (Souter, Stevens, Ginsburg, Breyer). Interesting opinions.