The Supreme Court is seen in Washington as the justices prepare to hand down decisions, Monday, June 17, 2019. (AP Photo/J. Scott Applewhite)
Washington CNN  — 

The Supreme Court on Thursday upheld the scope of a federal sex offender registration law.

The 2006 Sex Offender Registration and Notification Act requires sex offenders to register with the National Sex offender registry and update their registration when they travel or move.

Thursday’s 5-3 opinion turns away an effort to revive the “non-delegation doctrine” of the Constitution – a legal theory that holds that Congress can’t delegate its legislative power to other branches without giving the proper guidance.

But conservative justices suggested that they may embrace the principle to cut back on the power of federal agencies in the future.

A Maryland man, Herman Gundy, argued that Congress had unlawfully left it up to the attorney general to determine the law’s application as it applies to those who were convicted before its enactment.

The court disagreed in this case, saying that Congress had properly transferred its power to another branch of government when it passed the law.

“Indeed, if SORNA’s delegation is unconstitutional, then most of Government is unconstitutional – dependent as Congress is on the need to give discretion to executive officials to implement its programs,” Justice Elena Kagan wrote in the opinion.

Gundy pleaded guilty to sexual assault with a minor in Maryland in 2005, before the enactment of SORNA. After his release in 2012, he failed to register in New York and was subsequently charged with violating the law.

He challenged his indictment, arguing in part that Congress had delegated too much power to the Attorney General – to determine how the law applies retroactively – in violation of the “nondelegation” doctrine of the Constitution.

The Trump administration argued in favor of the federal law, saying Congress was not delegating its authority, but merely giving the attorney general guidance on how to apply the law, because it knew that there would be practical issues for the executive branch to address.

Only eight justices heard the case because it was argued before Justice Brett Kavanaugh took the bench.

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Kagan was joined by Justices Ruth Bader Ginsburg, Stephen Breyer and Sonia Sotomayor. Conservative Justice Samuel Alito concurred in the judgment but said he was doing so because there were not five justices available to “reconsider the approach we have taken for the past 84 years” because the case at hand was decided without Kavanaugh.

Future of nondelegation clause

Justice Neil Gorsuch, joined by Chief Justice John Roberts and Justice Clarence Thomas, wrote a fiery dissent, signaling impatience and an eagerness for the newly solidified conservative majority to move the court to the right.

“The Constitution promises not only the people’s elected representatives may adopt new federal laws restricting liberty,” Gorsuch wrote. He said the law at issue “scrambles that design.”

“It purports to endow the nation’s chief prosecutor with the power to write his own criminal code governing the lives of a half-million citizens,” he said. He noted that Alito supplied the fifth vote for the opinion but that even Alito acknowledged that future cases might be different when there are five conservatives.

“In a future case with a full panel, I remain hopeful that the Court may yet recognize that, while Congress can enlist considerable assistance from the executive branch,” Gorsuch said, adding, “it may never hand off to the nation’s chief prosecutor the power to write his own criminal code.”

“That is delegation running riot,” he said.

“Although the Court did not revisit the nondelegation doctrine in today’s ruling, all four of the conservative Justices who participated suggested that they have concerns with that principle, and want to revisit it in a future case,” said Steve Vladeck, CNN Supreme Court analyst and professor at the University of Texas School of Law.

Vladeck said that Justice Samuel Alito’s concurring opinion and Justice Neil Gorsuch’s dissent “strongly suggest that, in a future case in which Kavanaugh can participate, there may well be five votes to fundamentally reconsider Congress’s constitutional authority to delegate legislative and judicial power to administrative agencies.”

This story has been updated.