One of the most common attacks conservatives have made against progressive judges over the past five years is the claim that citing to decisions of courts of other countries constitutes a sure sign of liberal judicial activism. Fed by questions from Republican Senators, Chief Justice Roberts and Justice Alito both forcefully denounced this practice at their nomination hearings (despite their assertion that they could not take a position about just about every other legal issue), with Roberts colorfully asserting that this was akin to “looking out into a crowd and picking out your friends.” Just this morning, Republican Senator Jeff Sessions, recently chosen to be the ranking Republican on the Senate Judiciary Committee, repeated this claim on Morning Joe, attacking the Court’s “four or sometimes five liberals” for citing foreign cases and implying that he would vote against any nominee who had the temerity to suggest this was appropriate.

Repetition does not make these claims any less absurd. No judge we are aware of has asserted that the rulings of foreign courts should dictate how American judges interpret the U.S. Constitution, or be considered precedent that must be followed. The issue is whether American judges trying to resolve a dispute may look for guidance in how judges in other countries with similar legal systems have resolved similar disputes.

On that question, let’s start with first principles. Much of our Constitution is breathtakingly novel, but not all of it. Some terms — “the privilege of the writ of habeas corpus,” “bill of attainder” — were borrowed from English law, and no one has ever seriously questioned the propriety of citing the precedent of English courts in determining the meaning of these constitutional terms. Nor, certainly, were our framers averse to looking for guidance from the tribunals of other nations. On the contrary, in Federalist 63, James Madison and Alexander Hamilton urged “attention to the judgment of other nations,” explaining that “in doubtful cases, particularly where the national councils may be warped by strong passion or momentary interest, the presumed or known opinion of the impartial world may be the best guide that can be followed.”

It is also utterly uncontroversial for the Supreme Court to cite to foreign precedent when interpreting a treaty, something the Justices must do under the Supremacy Clause, which makes treaties part of the “supreme Law of the Land.” Even Justice Scalia — the Court’s harshest critic of the practice of looking to foreign decisions in constitutional cases — accepts that the Supreme Court must look to the decisions of foreign courts when interpreting treaties that the United States has signed. Indeed, in the 2004 case of Olympic Airways v. Husain, Scalia went so far as to dissent from the Court’s interpretation of a treaty because the majority did not give sufficient consideration to the views of courts in England and Australia, which had rejected the Court’s construction of the treaty.

So what precisely is Senator Session’s problem? The main answer, it seems, is that he and other conservatives don’t like the way the Supreme Court has interpreted the Eighth Amendment’s bar against “cruel and unusual punishments” to reflect “evolving standards of decency.” Justice Scalia and other conservatives have argued, based on a dubious reading of the Eighth Amendment’s text, that judges should look only at whether a punishment was considered cruel and unusual in 1789. Scalia thus wants judges to look only at old English precedents, not modern rulings from around the country and around the world. That’s a plausible, if ultimately unpersuasive, position on the Eighth Amendment, but it hardly supports a total ban on citing the work of foreign courts in cases dealing with American constitutional law. And the Court’s majority can hardly be criticized as “activist” for following the long-standing Eighth Amendment jurisprudence, which compels an inquiry into evolving standards of decency.

If American judges are required to consult foreign law when it comes to treaties, as well as old English cases about English equivalents to rights in our Constitution, it is hard to understand why American judges may never consider other foreign rulings when it comes to the Constitution, even when both the problem and the relevant legal standards are similar in the United States and the relevant foreign nation.

As Justice Ginsburg recently put it, “Why shouldn’t we look to the wisdom of the judge from abroad with at least as much ease as we would review a law review article written by a professor?” Conservatives should be forced to answer that unanswerable query every time they assert that it is improper for a judge to cite the ruling of a court of another country.

This post was written by Doug Kendall and David Gans. Doug Kendall is the President of Constitutional Accountability Center (CAC), a law firm, think tank and action center based in Washington DC, David Gans is CAC’s Human and Civil Rights Director. For more on the progressive promise of the Constitution’s text and history visit CAC’s website or blog.