Election officials in 27 states, most of them Republicans, have launched a program that threatens a massive purge of voters from the rolls. Millions, especially black, Hispanic and Asian-American voters, are at risk. Already, tens of thousands have been removed in at least one battleground state, and the numbers are expected to climb, according to a six-month-long, nationwide investigation by Al Jazeera America.

At the heart of this voter-roll scrub is the Interstate Crosscheck program, which has generated a master list of nearly 7 million names. Officials say that these names represent legions of fraudsters who are not only registered but have actually voted in two or more states in the same election — a felony punishable by 2 to 10 years in prison.

Until now, state elections officials have refused to turn over their Crosscheck lists, some on grounds that these voters are subject to criminal investigation. Now, for the first time, three states — Georgia, Virginia and Washington — have released their lists to Al Jazeera America, providing a total of just over 2 million names.

The Crosscheck list of suspected double voters has been compiled by matching names from roughly 110 million voter records from participating states. Interstate Crosscheck is the pet project of Kansas’ controversial Republican secretary of state, Kris Kobach, known for his crusade against voter fraud.

The three states’ lists are heavily weighted with names such as Jackson, Garcia, Patel and Kim — ones common among minorities, who vote overwhelmingly Democratic. Indeed, fully 1 in 7 African-Americans in those 27 states, plus the state of Washington (which enrolled in Crosscheck but has decided not to utilize the results), are listed as under suspicion of having voted twice. This also applies to 1 in 8 Asian-Americans and 1 in 8 Hispanic voters. White voters too — 1 in 11 — are at risk of having their names scrubbed from the voter rolls, though not as vulnerable as minorities.

If even a fraction of those names are blocked from voting or purged from voter rolls, it could alter the outcome of next week’s electoral battle for control of the U.S. Senate — and perhaps prove decisive in the 2016 presidential vote count.

“It’s Jim Crow all over again,” says the Rev. Joseph Lowery, who cofounded the Southern Christian Leadership Conference with Martin Luther King, Jr. Lowery, now 93, says he recognizes in the list of threatened voters a sophisticated new form of an old and tired tactic. “I think [the Republicans] would use anything they can find. Their desperation is rising.”