The Supreme Court on Friday made it harder to charge Capitol riot defendants with obstruction, a charge that also has been brought against former President Donald Trump.

The justices ruled 6-3 that the charge of obstructing an official proceeding, enacted in 2002 in response to the financial scandal that brought down Enron Corp., must include proof that defendants tried to tamper with or destroy documents. Only some of the people who violently attacked the Capitol on Jan. 6, 2021, fall into that category.

The decision could be used as fodder for claims by Trump and his Republican allies that the Justice Department has treated the Capitol riot defendants unfairly.

It's unclear how the court's decision will affect the case against Trump in Washington, although special counsel Jack Smith has said the charges faced by the former president would not be affected.

The high court returned the case of former Pennsylvania police officer Joseph Fischer to a lower court to determine if Fischer can be charged with obstruction. Fischer has been indicted for his role in disrupting Congress’ certification of Democrat Joe Biden’s 2020 presidential election victory over Trump.

Fischer is among about 350 people who have been charged with obstruction. Some pleaded guilty to or were convicted of lesser charges.

Chief Justice John Roberts wrote the court's opinion, joined by conservative Justices Samuel Alito, Neil Gorsuch, Brett Kavanaugh and Clarence Thomas, and by liberal Justice Ketanji Brown Jackson.

Reading the obstruction statute broadly "would also criminalize a broad swath of prosaic conduct, exposing activists and lobbyists to decades in prison,” Roberts wrote.

Justice Amy Coney Barrett dissented, along with Justices Elena Kagan and Sonia Sotomayor.

Roughly 170 Capitol insurrection defendants have been convicted of obstructing or conspiring to obstruct the Jan. 6 joint session of Congress, including the leaders of two far-right extremist groups, the Proud Boys and the Oath Keepers. A number of defendants have had their sentencings delayed until after the justices rule on the matter.

Some rioters have even won early release from prison while the appeal was pending over concerns that they might end up serving longer than they should have if the Supreme Court ruled against the Justice Department. They include Kevin Seefried, a Delaware man who threatened a Black police officer with a pole attached to a Confederate battle flag as he stormed the Capitol. Seefried was sentenced last year to three years behind bars, but a judge recently ordered that he be released one year into his prison term while awaiting the Supreme Court’s ruling.

Most lower court judges who have weighed in have allowed the charge to stand. Among them, U.S. District Judge Dabney Friedrich, a Trump appointee, wrote that “statutes often reach beyond the principal evil that animated them.”

But U.S. District Judge Carl Nichols, another Trump appointee, dismissed the charge against Fischer and two other defendants, writing that prosecutors went too far. A divided panel of the federal appeals court in Washington reinstated the charge before the Supreme Court agreed to take up the case.

More than 1,400 people have been charged with Capitol riot-related federal crimes. Approximately 1,000 of them have pleaded guilty or been convicted by a jury or a judge after a trial.

The U.S. attorney’s office in Washington, which has handled Jan. 6 prosecutions, said no one who has been convicted of or charged with obstruction will be completely cleared because of the ruling. Every defendant also has other felony or misdemeanor charges, or both, prosecutors said.

For around 50 people who were convicted, obstruction was the only felony count, prosecutors said. Of those, roughly two dozen who still are serving their sentence are most likely to be affected by the ruling.