Hi, welcome to Unit 1.4 in Policy-Based Cannons. We're going to go over several canons that are based on policy, so this is not language in the statute or even sources outside the statute, like legislative history. These are based purely on policy decisions. So one is called the Rule of Lenity, and this comes up most often in criminal cases. The idea is that you shouldn't find a defendant guilty of violating a statute when it isn't really clear that certain behavior was prohibited under that statute.
So if after applying other sources of statutory interpretation, the statute remains ambiguous, then what we want to do is construe that statute in favor of the defendant, to show leniency by construing the statute in favor of the defendant. And this policy canon is based on constitutional notions of due process. Due process traditionally requires requires at least adequate notice and fair procedures. And if the statute is so unclear that a court can't figure out what it means, then we assume it didn't really give adequate notice to the defendant.
But it's not only limited to criminal cases. There are some types of civil cases that impose penalties so severe that we would compare them to criminal punishment. And a good example of this would be an immigration... case that's technically civil, but has a penalty of deportation. In those cases also, courts apply the rule of lenity to construe the Immigration Act in a way that is in favor of the immigrant facing deportation when the statute is otherwise totally ambiguous.
And remember that this is a canon of last resort. It's never the reason, the initial reason the court will interpret a statute a certain way. It's usually when everything else is a tiebreak. is a tie, this policy canon could be a tiebreaker. So another policy canon is the presumption against a change in the common law.
So normally judges want to follow the common law, and if a certain interpretation is a deviation from the common law, or the word derogation, meaning deviation is used often, then that interpretation deviating from the common law is disfavored. So the only time a judge would really want to alter the common law understanding would be if that is plainly, clearly what Congress wanted. A third policy canon deals with retroactivity.
Retroactivity means applying a statute to behavior that occurred before the statute became effective. So civil statutes and criminal statutes are treated a little bit differently in this regard. For civil statutes, we generally assume them to be prospective, meaning they apply only after the effective date of the statute.
But that presumption can be rebutted in a couple situations. One is where Congress provides a clear statement of retroactivity. And second of all, where that retroactive application would not impair a vested right. For criminal statutes, we actually have a constitutional provision that's relevant, which is the ex post fact. And the ex post facto clause of the Constitution prohibits retroactive application of penal or criminal statutes.
And the last policy canon we're going to talk about is the doctrine of constitutional avoidance, which actually comes up quite a lot. What this doctrine says is that when there are two reasonable interpretations of a statute, one of which raises a constitutional issue and the other doesn't, the court would adopt the one that does not raise a constitutional issue. So there's a couple aspects of this I want to highlight.
One is that both interpretations have to be reasonable for this doctrine to apply. If only one is reasonable and the other is absurd or ridiculous, the court is not going to apply this doctrine. So both interpretations have to be reasonable. The second thing to remember is that the court doesn't have to decide that one of the interpretations would violate the Constitution. It only has to raise a serious constitutional question.
The court does not have to resolve that question. It just says, because this one interpretation raises these serious constitutional concerns, we're going to go with the other one, the other reasonable interpretation that doesn't raise these concerns. It's important to remember, too, though, that courts do strike down statutes for being unconstitutional. So a court does not always have to avoid a constitutional issue. It can actually just plainly decide that the statute's unconstitutional.
So an example of this would be the Supreme Court's decision in United States v. Windsor in 2013, which struck down the Defense of Marriage Act as unconstitutional under the Due Process Clause. That act defined marriage as between a man and a woman. And the court found that it violated due process. And Justice Kennedy, who wrote that opinion, said that the federal statute is invalid for no legitimate purpose, overcomes the purpose and effect to disparage and injure those whom the state, by its marriage law, sought to protect in personhood and dignity. So that concludes our brief discussion of policy canons.
And next, we're going to turn to extrinsic sources in the legislative process. So sources outside the statute.