Once used mostly to check immigrants’ eligibility for public benefits, SAVE has undergone a dramatic expansion over the last year at the behest of President Donald Trump, who has long falsely claimed that millions of noncitizens lurk on state voter rolls, tainting American elections.

At Trump’s direction, DHS has pooled confidential data from across the federal government to enable states to mass-verify voters’ citizenship status using SAVE. Many of the nation’s Republican secretaries of state have eagerly embraced the experiment, agreeing to upload all or part of their rolls.

But an examination of SAVE’s rollout by ProPublica and The Texas Tribune reveals that DHS rushed the revamped tool into use while it was still adding data and before it could discern voters’ most up-to-date citizenship information.