As the once-per-decade redistricting fight gets underway, voters will be armed with a new arsenal: a suite of sophisticated digital tools capable of exposing suspected partisan gerrymandering as it unfolds.

The rollout of this civic-minded tech offensive comes amid fears that the upcoming redistricting process, which officially begins Thursday with the release of Census Bureau data, could see an unprecedented scramble to manipulate voting maps for partisan gain.

A leading advocate in the fight will be the Princeton Gerrymandering Project. The group plans to issue “report cards” that assess map proposals for things like fairness and competitiveness, giving the public a chance to weigh in before the proposed maps are locked in for the next decade.

“It's the possibility that citizens and reform groups can talk back,” said Sam Wang, the project’s director. “That report card can be used to demonstrate to legislators the consequences of their actions, and to create a record on the spot that can then be used to perhaps, ideally, draw fair lines before they become law.”

Gerrymandering, the practice of drawing congressional and state legislative districts to dilute an opposing party’s voting power, has been around roughly since the nation’s founding. But experts say this latest round of redistricting is uniquely susceptible to partisan manipulation.

No federal check currently exists to blunt the practice. Several bills in Congress, including the Democratic-backed For the People Act, would ban partisan gerrymandering, but the measures face a steep uphill climb. And as a result of a 2019 decision by the Supreme Court, federal judges are prohibited from reviewing even the most egregious allegations.

Although state lawmakers from both parties have engaged in the practice, some analysts say Republicans could retake the House in 2022 by increasing the partisan skew of maps in Florida, Georgia, North Carolina and Texas alone.

And since last decade’s redistricting, which gave the GOP a tremendously lopsided partisan advantage, the technology used to design reliably gerrymandered districts has only grown more sophisticated.

But groups like the Princeton Gerrymandering Project aim to confront anti-democratic technology with pro-democratic technology. Its flagship product is the Redistricting Report Card, a collaborative effort with the nonprofit anti-corruption group RepresentUs.

The project has researchers plug U.S. census data into an algorithm that generates 1 million hypothetical maps for each state, establishing a grading curve that accounts for a full range of possibilities, from maps that are very fair to very unfair. When a state unveils a proposed map, the algorithm will assign it a letter grade.

“We thought that by taking these mathematical ideas and turning them into a report card, it would be more palatable, more easy to understand and easier to communicate,” said Wang, the group’s director, who teaches neuroscience at Princeton University.

The watchdog technology will help shed light on map-drawing techniques known as “cracking” and “packing,” hallmark features of gerrymandering.

Cracking breaks up a geographic cluster of an opposing party’s likely voters and distributes them among several districts where their votes are unlikely to make a difference. Alternatively, packing those voters into a small number of districts virtually ensures the opposing party will be uncompetitive in most districts.

These mapping strategies can produce unwieldy results, as the very name of the practice indicates. In 1812, Massachusetts Gov. Elbridge Gerry approved a partisan district that was so oddly shaped it was said to resemble a salamander, which, combined with his surname, made “gerrymander.”

According to a recent analysis by RepresentUs, 35 states pose an extreme or high risk of gerrymandering, where politicians wield either total control over redistricting, or face few if any meaningful checks on partisan maneuvering.

Similarly, a new study by the liberal nonprofit Brennan Center listed four states with GOP-held legislatures — Georgia, Florida, North Carolina and Texas — as possessing the highest risk of extreme gerrymandering. Those states could draw anywhere from six to 13 new congressional districts that heavily favor GOP candidates — which would be enough for Republicans to retake the House in 2022 — according to findings from the Democratic data firm TargetSmart that were reported by the progressive outlet Mother Jones.

Another group that plans to police gerrymandering is the Campaign Legal Center (CLC), a nonprofit government watchdog and advocacy firm. Like the Princeton project, CLC’s PlanScore platform will analyze new district map proposals to detect possible partisan skew. With district maps dating back to the 1970s, CLC says its analytics represent “the most comprehensive historical dataset of partisan gerrymandering ever assembled.”

“Voting districts drawn this year will shape our lives and our communities for the next decade,” said Ruth Greenwood, director of the Election Law Clinic at Harvard Law School and a founder of PlanScore. “But first, to understand the impact of gerrymandering on our voting maps, we need to be able to measure it."