The Supreme Court on Tuesday appeared divided over whether the federal government had properly charged hundreds of alleged Jan. 6 rioters with felony obstruction, with several justices voicing concern that prosecutors' broad interpretation of a financial crimes law could be weaponized against political protests.

The high-stakes case, brought by a former Pennsylvania police officer facing charges for his alleged conduct at the Capitol in 2021, could upend the convictions and sentences of more than 300 defendants -- and could also potentially invalidate two of the four charges against former President Donald Trump brought by special counsel Jack Smith.

At issue in the case of Fischer v. United States is whether the Sarbanes-Oxley Act of 2002, enacted in the wake of the Enron scandal to prevent the destruction of evidence in financial crimes, can be used against alleged participants in the events of Jan. 6, 2021, which disrupted congressional certification of electoral votes from the 2020 presidential election.

The statute makes it a crime to "alter, destroy, mutilate or conceal a record, document or other object" in an effort to impair an investigation. But it also includes a catch-all provision for conduct that "otherwise obstructs, influences or impedes any official proceeding."

Joseph Fischer's defense attorney Jeffrey Green argued the provision should not apply to his client.

"Attempting to stop a vote count or something like that is a very different act than actually changing a document or altering a document or creating a fake new document," Green told the court on Tuesday. The law is "about a direct effect ... on evidence that's to be used in a proceeding."

Biden administration Solicitor General Elizabeth Prelogar said the text of the statute couldn't be clearer and that Congress intended it to be expansive.

"The case as it comes to this court presents a straightforward question of statutory interpretation: Did [the] petitioner obstruct, influence or impede the joint session of Congress?" Prelogar told the justices. "The answer is equally straightforward. Yes, he obstructed that official proceeding."

The high court's three liberal justices appeared, at times, to lean toward a plain reading of the statute that would allow most, if not all, of the charges to stand.

"There's a good case that this provision -- everybody knew it was going to be superfluous because it was a provision that was meant to function as a backstop" to catch conduct that Congress did not explicitly enumerate, Justice Elena Kagan said.

But members of the court's conservative majority seemed more skeptical, focusing on the lack of prosecutions under the same law for matters unrelated to financial or documentary crimes. Chief Justice John Roberts indicated the obstruction language in the law must be considered in context.

A "general phrase is controlled and defined by reference to the terms that precede it," Roberts said of the court's precedent, nodding to references about documents and records.

"What happened on January 6 was very, very serious. But we need to find out what are the outer reaches of this statute under your interpretation," Justice Samuel Alito told Prelogar.

What if "all the bridges from Virginia were blocked, and members [of Congress] from Virginia who needed to appear at a hearing couldn't get there or were delayed in getting there? Would that be a violation of this provision?" Alito asked.

"It sounds to me like that wouldn't satisfy the 'proceeding' element," Prelogar said.

Justice Amy Coney Barrett raised similar concerns, wondering if protestors had not breached the Capitol but still had a goal of impairing or stopping the proceeding by making their voices heard. "Does that violate the statute in your view under this impede language?" she asked.

Joseph Fischer was a participant in the "Save America" rally on Jan. 6 who faces prosecution for allegedly being part of the crowd that entered the Capitol as Congress was attempting to certify the 2020 election results.

The statute carries a 20-year maximum sentence, though most Jan. 6 defendants have received far more lenient penalties in addition to being charged with other, related crimes.

The court could uphold lower court rulings that affirmed the government's broad interpretation of the law, or it could narrow the obstruction statute in some way or otherwise make clear it doesn't apply to the circumstances of Jan. 6.

A decision in the case is expected by the end of June.