SAN ANTONIO, Texas Lawyers for the state of Texas defended a Republican-led effort to question the voting rights of tens of thousands of naturalized citizens at a hearing Tuesday, casting blame for flaws in the process on local officials.

Tuesdays hearing in a U.S. District Court in San Antonio marked the first courtroom challenge to the Texas crackdown on suspected noncitizen voting in the countrys most populous red state. The class action lawsuit asks Judge Fred Biery to issue an injunction halting the voter probe.

Texas Secretary of State David Whitley (R) announced on Jan. 25 that his office had identified some 95,000 noncitizen voters , including 58,000 who had cast a ballot at some point in the last two decades. State officials had compiled a list of suspected ineligible voters by checking voting registrations against records kept by the Department of Public Safety, which issues drivers licenses and state identification cards.

The list, however, appears to consist almost entirely of immigrants who were not U.S. citizens when they last requested or renewed a drivers license or state ID but who later naturalized. Applicants have to declare their citizenship status when requesting those documents, but the department doesnt ask people to notify it if their status changes.