flySnow/iStockBY: DEVIN DWYER, ABC NEWS

(WASHINGTON) —As Republicans in nearly every state push new voting restrictions in the aftermath of the 2020 election, the U.S. Supreme Court on Tuesday will hear a major case to decide how those new rules should be judged under federal civil rights law.

State legislators in at least 43 states are considering more than 250 bills that would make it harder to vote, according to the Brennan Center for Justice, a nonpartisan voter advocacy group tracking the trend. Sponsors of the measures said they're necessary to prevent fraud; civil rights advocates claim they primarily suppress minority voters who overwhelmingly back Democratic candidates.

At the heart of the case is the landmark Voting Rights Act of 1965, which prohibits racial discrimination in voting and lays out the standard for determining when it exists. Section 2 of the law says any measure which "results in a denial or abridgment of the right of any citizen of the U.S. to vote an account of race or color" is illegal.

That provision has never been tested at the Supreme Court and is considered a critical remaining safeguard after the court's conservatives in 2013 effectively ended the VRA's requirement that states with a history of racial discrimination pre-clear new voting rules with the Justice Department.

"The court needs to send a strong statement that the Voting Rights Act will be there for the American public, especially at a time when we see politicians in states trying to put barriers in front of the ballot box," said Myrna Perez, an attorney and election law expert at the Brennan Center.

More than 159 million Americans voted in 2020 -- 66.8% of the eligible voting population -- a historic turnout not seen in more than a century thanks in part to the surge in voting by mail.

The case to be argued Tuesday centers on two Arizona election laws that Democrats say discriminate against Native American, Latinx and African American voters. One requires election officials to discard any ballots cast in the wrong precinct. The other measure bans third-party ballot collection.

"Ninety-six percent of non-native American people live on a postal route, but only 26% of Native Americans do. If people have less access to mail, then getting that ballot back is a big deal," said Alex Gulotta, an Arizona voting rights advocate. "It would make you jump through a bunch of hoops to be able to cast a mail-in ballot.”

Roughly 80% of Arizona voters cast ballots by mail or in-person at drop boxes, according to state election officials. For years, until state Republicans moved to ban the practice in 2016, independent advocacy and community groups helped to collect ballots and submit them together.

While many states toss out-of-precinct ballots, Arizona does so at a far higher rate in a way that "disproportionately affects minority voters," the Ninth Circuit Court of Appeals concluded in the case, siding with Democrats.

Arizona Republicans, who are appealing the circuit decision, insist the measures are race-neutral, affording equal opportunity for all voters under the rules.

"You have to look at our voting system in total," said Arizona Attorney General Mark Brnovich, a Republican and first generation immigrant from Montenegro, who is defending the law before the court. "In Arizona, you can vote early; there's no-excuse absentee voting ... we have drop-off locations. So, there are a lot of ways that people can vote and we just want to make sure that they're secure.”

Brnovich also argued that, while there may not be evidence of widespread fraud or abuse involving out-of-precinct voting or third-party ballot collection in his state, Arizona has the right to proactively take steps to reduce risk.

"This shouldn't be like a right versus left. To us, it's a fundamental issue of right versus wrong. It's all about the integrity," Brnovich said. "These measures are designed to provide order and secure the elections and provide confidence in the results."

In a letter to the court, the Biden administration says it agrees that the Arizona laws may not violate Section 2 of the Voting Rights Act but suggests the justices do not need to go further and establish limits for future cases involving allegations of discrimination.

Republicans want the justices to set a high bar for assessing when voting rules "deny or abridge" the right to vote. Democrats and civil rights advocates want the court to maintain a broad standard that considers the totality of circumstances surrounding the rules, especially the impact on communities of color.

"We just got out of an election with historic turnout, one that saw communities who have been totally marginalized or disenfranchised participating in record numbers," said Perez. "More than ever, we need to be sensitive to the needs of communities of color and all Americans having their voices heard."

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