What it says on the can. What if the doctrine of judicial review had never been established by the Supreme Court of the United States. The POD can be whatever you'd like. Personally, I don't think butterflying Marbury v. Madison would be sufficient. Judicial review would still have been established at a later date through another case. Certainly it was an established concept that was discussed favorably at the Constitutional Convention, was treated as an assumed power of the federal judiciary by the state ratifying conventions, and was already practiced by state courts with respect to their state constitutions. As such, I think a POD will have to be relatively early in the US' history. Before the Constitution probably. That said, please speculate on what the affects of no judicial review at the federal level would be.