WASHINGTON, DC - SEPTEMBER 28: People walk past the U.S. Supreme Court on September 28, 2020 in Washington, DC. This week Seventh U.S. Circuit Court Judge Amy Coney Barrett, U.S. President Donald Trump's nominee to the Supreme Court, will begin meeting with Senators as she seeks to be confirmed before the presidential election. (Photo by Al Drago/Getty Images)
CNN  — 

As emergency petitions concerning voting rights challenges have raced through the courts in the final weeks of the election, judges and justices have found themselves trying to explain a legal doctrine that was designed to preserve the integrity of the electoral process.

But for a doctrine aimed at clarity, it has, in the age of coronavirus, raised plenty of confusion on its own, and it could swing the presidential election. At issue: When should courts refrain from changing voting rules too close to an election in order to avoid causing voter confusion?

The so-called “Purcell Principle” arises out of a 2006 Supreme Court case concerning a strict voter-identification law. A federal appeals court blocked the law pending appeal. But the Supreme Court stepped in and allowed the law to take effect.

In doing so, the Supreme Court sent a strong message to federal courts: “Court orders affecting elections, especially conflicting orders, can themselves result in voter confusion and consequent incentive to remain away from the polls.”

The justices made a point of noting they weren’t ruling on the merits of the dispute, but instead seeking to avoid a last-minute change that would confuse voters too close to an election.

“Given the imminence of the election and the inadequate time to resolve the factual disputes, our action today shall of necessity allow the election to proceed without an injunction suspending the voter identification rules,” the court held.

In a nutshell: Don’t step in and change the status quo too close to an election because it’s a disservice to voters.

But the resounding question of late, as Covid has prompted adjustments to voting rules, has been the exact definition of the status quo and the precise timeline for when a change comes too close to an election. Lawyers from both sides of recent disputes have argued that their proposed rules represent the status quo that shouldn’t be changed.

To some, Purcell has become a guiding principle to avoid voter confusion. To others, it is an opaque doctrine in need of further clarification.

For instance, in South Carolina, a district court blocked the state’s requirement that a witness sign an absentee ballot, citing the pandemic.

The 4th US Circuit Court of Appeals eventually affirmed the ruling, but Judge J. Harvie Wilkinson III wrote a scathing dissent. Wilkinson said his colleagues were disregarding that the Supreme Court has “repeatedly cautioned us not to interfere with state election laws in the weeks before an election.” Wilkinson said he shared concerns about Covid but that the “pandemic does not give judges a roving commission to rewrite state election codes.”

The Supreme Court ultimately agreed with Wilkinson and granted a request to reinstate the requirement. Justice Brett Kavanaugh explained his reasoning, which was based in part on Purcell.

“For many years, this Court has repeatedly emphasized that federal courts ordinarily should not alter state election rules in the period close to an election,” Kavanaugh said. Left unsaid was that the Supreme Court, by reinstating the witness requirement, was itself changing the status quo.

A case out of Wisconsin concerning an extension of voting deadlines by six days pits Democrats against Republicans, with lawyers on both sides arguing that Purcell works in their favor.

Democratic lawyer Marc Elias urges the court to allow the extension. Quoting Purcell, Elias argues that “confidence in the integrity of our electoral process is essential to the functioning of our participatory democracy.”

Elias said confidence in Wisconsin’s electoral process will be shattered if “tens of thousands of valid, timely cast absentee ballots are not counted because they arrived two or three days after the election due to mail delays and other factors beyond the voters’ control.”

But Misha Tseytlin, a lawyer for the Republican National Committee, said Purcell works in his favor. “Federal courts should ordinarily not alter the election rules on the eve of an election,” he wrote.

The Supreme Court has yet to rule.

Election law expert and CNN contributor Rick Hasen has coined the term “Purcell Principle” and said it needs tweaking.

In a 2016 law review article, Hasen said the court was right in Purcell to “note special considerations in election cases,” because voters could be not only confused but also disenfranchised. They could, for example, show up without the right documentation or at the wrong polling place. But he said those interests should not be the sole consideration of a court.

Hasen said courts should also consider factors such as the likelihood of success of the case on the merits, and the potential irreparable harm to both sides.

Early next week, Amy Coney Barrett is set to take the seat left vacant by Justice Ruth Bader Ginsburg’s death. Her view on Purcell might represent the deciding vote.

Ginsburg spent an all-nighter back in 2014 writing a dissent when the majority allowed a Texas voter-identification law to go into effect, citing Purcell. Joined by fellow liberal Justices Elena Kagan and Sonia Sotomayor, Ginsburg said that in her mind the status quo was not the new law, but the fact that for a decade prior a less restrictive law had been in place. And she rejected the notion that the court, by stepping in, could negatively impact the election.

“The greatest threat to public confidence in elections,” she wrote, “is the prospect of enforcing a purposefully discriminatory law, one that likely imposes an unconstitutional poll tax and risks denying the right to vote to hundreds of thousands of eligible voters.”