Here’s Virginia House Bill 825, proposed in the 2012 session:

§ 8.01-465.26. Application of foreign laws. A. For purposes of this chapter, unless the context requires a different meaning: “Foreign law” means any constitution, law, legal code, or legal system that is established outside the jurisdiction of the United States, the District of Columbia, or the states or territories of the United States. B. No justice, judge, or other judicial officer of any court of the Commonwealth shall decide any issue in a case or action before that court, and no judge, hearing officer, or other official of any administrative agency, department, or commission shall decide any issue in any adjudication, rule-making, or other administrative proceeding before that agency, department, or commission, in whole or in part based on the authority of foreign law except to the extent that the United States Constitution or Constitution of Virginia or any federal or state law requires or authorizes the consideration of such foreign law.

But wait — judges already can only consider any law only to the extent that federal or state law “authorizes” the consideration of the law. To be sure, such law (often common law) often authorizes such consideration; choice of law rules authorize (or even require) consideration of foreign law, contract law authorizes (or even requires) consideration of foreign law when the contract calls for it. And if consideration of foreign law isn’t authorized, then the judge’s decision would already be legally mistaken. Even the controversial Supreme Court decisions of the last decade that relied on foreign law relied on precedents that “authorize[d] the consideration of such federal law.”

Of course, if “law” here refers to “statute” and excludes common-law rules, the proposal would have a great deal of effect — bad effect, since that means that common-law choice of law rules (and most choice of law rules are common law) would be abrogated, and Virginia courts would be barred from considering foreign law in deciding the validity of foreign marriages and divorces, the enforceability of foreign judgments, the interpretation of contracts that call for application of foreign law, the resolution of tort disputes based on injuries in foreign nations, and so on. But I doubt that “law” would mean something this restrictive, given that in our legal system so many “laws” are in fact rules of the common law.