More than 50 years ago, President Lyndon B. Johnson signed the Voting Rights Act of 1965 into law. Yet decades later, voting rights remain a frontier of partisan and racially charged debates due to a Supreme Court ruling that severely weakened the federal law and triggered a wave of new court battles over the issue.

The latest battleground in this debate: North Carolina. Civil rights groups, joined by the US Department of Justice, are challenging a 2013 North Carolina law that requires a photo ID for all residents to vote, eliminated some early voting days, ended same-day voter registration and out-of-precinct voting, and stopped the preregistration of 16- and 17-year-olds in the state.

But on Monday, the US Supreme Court effectively let the state's law remain dead by refusing to review a lower court decision that repealed it. Chief Justice John Roberts wrote in a brief statement that the refusal did not mean the court agreed with the lower court's decision, pointing instead to some procedural questions over who was allowed to appeal the previous ruling on North Carolina's behalf. But the Supreme Court's move nonetheless means the ruling against the law will remain in place — at least for now.

In July 2016, the US Fourth Circuit Court of Appeals ruled against North Carolina's law, overturning a lower court decision that had ruled in favor of the legislation. The court was unambiguous in its ruling: It found that North Carolina's law "target[ed] African-Americans with almost surgical precision."

Judge Diana Gribbon Motz, who wrote most of the opinion in North Carolina State Conference of the NAACP v. McCrory, cited the state's own testimony to explain her decision (emphasis mine):

As "evidence of justifications" for the changes to early voting, the State offered purported inconsistencies in voting hours across counties, including the fact that only some counties had decided to offer Sunday voting. … The State then elaborated on its justification, explaining that "[c]ounties with Sunday voting in 2014 were disproportionately black" and "disproportionately Democratic." … In response, SL 2013-381 did away with one of the two days of Sunday voting. … Thus, in what comes as close to a smoking gun as we are likely to see in modern times, the State's very justification for a challenged statute hinges explicitly on race — specifically its concern that African Americans, who had overwhelmingly voted for Democrats, had too much access to the franchise.

Advocates widely expected the case to eventually end up at the Supreme Court, which could have decided the constitutionality and legality of laws like North Carolina's that Republican legislators across the country are pushing for more and more. The Supreme Court's decision to not review the Fourth Circuit Court of Appeals ruling means that will not happen for the time being.

What the North Carolina law did

North Carolina's Republican-dominated state legislature passed the law in 2013 after a Supreme Court ruling struck down a key measure in the Voting Rights Act, allowing North Carolina — which has a history of discrimination against black voters — to proceed with its new restrictions without approval from the federal government.

The North Carolina Senate had been working on what it called a voter ID bill prior to the Supreme Court ruling. But after the court's decision, State Sen. Tom Apodaca (R) said, "Now we can go with the full bill" — passing what the Brennan Center for Justice characterized as "one of the most restrictive voting laws since the Jim Crow era."

In Shelby County v. Holder, the Supreme Court struck down the formula in Section 4 of the Voting Rights Act used to establish which states had to get preclearance from the Justice Department before enacting major changes to their voting laws, based on the states' history of discrimination against black voters. This removed North Carolina from the federal government's watch list, allowing the state to pass its voting restrictions without federal supervision.

But the Supreme Court left in place Section 2 of the Voting Rights Act, which "prohibits voting practices or procedures that discriminate on the basis of race, color, or membership in one of the language minority groups." It's under this section of the federal law that civil rights advocates and the Justice Department are challenging the voting law in North Carolina.

"You cannot enact laws that deny or diminish the right to vote for African Americans and Latinos," Donita Judge, an attorney with the Advancement Project, a civil rights group, previously told me. "We believe that this law has a greater impact on African Americans and Latinos — and that's unconstitutional."

In the appeals court ruling, Judge Motz said this is exactly what North Carolina was doing. Motz concluded that the state's law not only had a racially disparate impact, but that the state intentionally discriminated. That's critical, because courts are much more likely to rule something as discriminatory if an intent to discriminate is proven, instead of only finding that something had a discriminatory, but perhaps unintentional, result.

Beyond the state's own testimony above, Motz pointed to a very clear-cut example of the state intentionally discriminating: "In particular, African Americans disproportionately used the first seven days of early voting. … After the receipt of this racial data, the General Assembly amended the bill to eliminate the first week of early voting, shortening the total early voting period from seventeen to ten days."

Now, with the Supreme Court's refusal to review, that ruling will remain in place.

Voting restrictions hurt minority voters most

Several studies have found that voting restrictions disproportionately hurt minority voters.

One widely cited 2006 study by the Brennan Center found voter ID laws, for instance, disproportionately impacted eligible black voters: 25 percent of black voting-age citizens did not have a government-issued photo ID, compared with 8 percent of white voting-age citizens. And a study for the Black Youth Project, which analyzed 2012 voting data for people ages 18 to 29, found 72.9 percent of young black voters and 60.8 percent of young Hispanic voters were asked for IDs to vote, compared with 50.8 percent of young white voters.

So why is it burdensome for these voters to get a photo ID? Since minority Americans are less likely to have flexible work hours or own cars, they might have a harder time affording a voter ID or getting to the right place (typically a DMV or BMV office) to obtain a voter ID, rely more on early voting opportunities to cast a ballot, or require a nearby voting place instead of one that’s a drive, instead of a walk, away from home or work.

For civil rights groups, the restrictions harken back to the days of poll taxes, literacy tests, and other rules that were imposed to block minorities from voting prior to the Voting Rights Act. Like modern voting restrictions, the old laws didn't appear to racially discriminate at face value — but due to selective enforcement and socioeconomic disparities, they disproportionately kept black voters out.

This is politically beneficial for Republicans: Minority voters tend to go Democrat, so any voter suppression effort that disproportionately hurts minority voters will likely benefit the GOP.

Some Republicans, including an operative in North Carolina, have even admitted that this is the goal of the new wave of voting restrictions. As William Wan reported for the Washington Post:

Longtime Republican consultant Carter Wrenn, a fixture in North Carolina politics, said the GOP’s voter fraud argument is nothing more than an excuse. "Of course it’s political. Why else would you do it?" he said, explaining that Republicans, like any political party, want to protect their majority. While GOP lawmakers might have passed the law to suppress some voters, Wrenn said, that does not mean it was racist. "Look, if African Americans voted overwhelmingly Republican, they would have kept early voting right where it was," Wrenn said. "It wasn’t about discriminating against African Americans. They just ended up in the middle of it because they vote Democrat."

This claim is key to the legal challenges against North Carolina's law: By proving that the state's law has a disproportionate racial impact, and that it intended to discriminate and suppress a certain group of voters, it justify a repeals the law through Section 2 of the Voting Rights Act.

Now, the research shows that voter ID laws and other voting restrictions have a fairly small overall impact on elections, at most reducing turnout by a percentage point or two.

But even if voting restrictions don't have a big effect on the ultimate outcome of elections, they still appear to disproportionately keep minority voters from exercising their most basic democratic right — a problem no matter how you slice it. And it's a problem that's perpetuated through a total myth: a false claim that there's a lot of voter fraud in America, when the evidence simply shows otherwise.

Voting restrictions supposedly aim to stop voter fraud

Supporters of voting restrictions generally argue that outright discrimination isn't their intent.

The main goal of voting restrictions like North Carolina's, they say, is to limit the potential for voter fraud — by requiring a photo ID to vote and reducing the number of days in which someone could show up and fraudulently vote. And they claim that these measures aren't burdensome enough to stop someone from voting.

But the type of in-person voter fraud these initiatives target is nonexistent to extremely rare. Loyola Law School professor Justin Levitt has tracked credible allegations of in-person voter impersonation for years, finding 35 total credible allegations between 2000 and 2014, when more than 800 million ballots were cast in national general elections, and hundreds of millions more were cast in primary, municipal, special, and other elections.

A more recent investigation in North Carolina by the State Board of Elections found just one — out of nearly 4.8 million total votes in 2016 — credible case of in-person voter fraud. That amounts to just 0.00002 percent of all votes. Other types of fraud were very rare as well: Although there were more than 500 ineligible votes, the State Board of Election found that almost all of these were due to people negligently voting when they genuinely thought they were allowed to vote but legally weren't. It was simply not the case that there were a lot of people trying to rig the election.

Another investigation, conducted by the News21 journalism project in 2012, looked at all kinds of voter fraud nationwide, including voter impersonation, people voting twice, vote buying, absentee fraud, and voter intimidation. It confirmed that voter impersonation was extremely rare, with just 10 credible cases.

But the other types of fraud weren’t common either: In total, the project uncovered 2,068 alleged election fraud cases from 2000 through part of 2012, covering a time span when more than 620 million votes were cast in national general elections alone. That represents about 0.000003 alleged cases of fraud for every vote cast, and 344 fraud cases per national general election, in each of which between 80 million and 135 million people voted. The number of fraudulent votes was a drop in the bucket.

What’s more, not all — maybe not even half — of these alleged fraud cases were credible, News21 found: "Of reported election-fraud allegations in the database whose resolution could be determined, 46 percent resulted in acquittals, dropped charges or decisions not to bring charges."

That doesn’t mean voter fraud has never happened and never had an impact. The New York Times, for instance, reported on a 1997 case in which it was revealed that Miami Mayor Xavier Suárez clinched his electoral victory "with the help of hundreds of absentee ballots bearing the names of dead people, felons and other ineligible voters." While Suárez was never charged, he was eventually forced to step down from office after an appellate court threw out the absentee ballots.

But this type of situation, the empirical evidence and experts suggest, is likely far too rare to swing much bigger elections. When debating whether to do something about voter fraud, then, it’s important to consider whether the potential downsides — such as making it harder for people of color to vote or sowing doubt in US elections — are worth the upside of stopping a tiny number of fraudulent votes.

Yet Republican lawmakers in particular have passed an array of measures that restrict access to the vote. According to the Brennan Center, 14 states passed new voting restrictions — from strict photo ID requirements to new limits on early voting — that were in place for the 2016 election: Alabama, Arizona, Indiana, Kansas, Mississippi, Nebraska, New Hampshire, Ohio, Rhode Island, South Carolina, Tennessee, Texas, Virginia, and Wisconsin. Other states passed restrictions, but they're currently tied up in court battles.

Some of the laws outside North Carolina have also been challenged in court. And despite a big victory in North Carolina, activists expect the fight to continue.

"We call this our Selma because this is the worst attack on voting rights we've seen since the days of Jim Crow," William Barber, president of the North Carolina NAACP, previously told me. "The government should not be in the business of making it harder to vote. That should just not be the case."