The demand is the size of the state; the error was the size of a rounding line. New Jersey disclosed this week that a vendor's software bug had registered roughly 6,600 people who answered 'no' to the citizenship question, fewer than 400 of whom voted, with no evidence any result changed [2]. The Justice Department's response is to ask for everyone.
The Civil Rights Division, under Assistant Attorney General Harmeet Dhillon, is citing the state's disclosure as an 'additional basis' in an existing lawsuit - US v. Caldwell, filed in the District of New Jersey in February - to obtain the state's complete, unredacted voter file [1]. A letter to Governor Sherrill demands, within five business days, full names, dates of birth, nationalities, addresses, and registration and voting records including mail-ballot certifications [1].
Dhillon's stated reason is the same phrase the administration has used all week: 'Ensuring that US citizens' votes are not illegally diluted by noncitizens' votes is of paramount importance' [1]. The request predates the glitch - the suit was filed in February - and the glitch is now the hook for it [1].
One piece of context the demand leaves out: a federal judge has already blocked the administration from repurposing the Social Security database for voter checks, in part because it false-flags newly naturalized citizens - Americans - as ineligible [2]. The tool the government wants to point at New Jersey's rolls has a documented history of marking the wrong people.
The proportion is the record here. A discrete, self-reported error the state caught and is fixing has become the justification for federal access to the personal data of every registered voter in New Jersey [1][2]. Governor Sherrill notes the affected registrants are politically diverse and that no result changed [2] - which is the part the 'additional basis' is built to move past.