A federal appeals court on Monday night briefly lifted a block on the Trump administration's efforts to investigate alleged voting by noncitizens in California, only to reverse course hours later. The full 11-judge 9th Circuit Court of Appeals will now rehear the case, restoring a temporary restraining order that had barred the administration from making further requests to set aside ballots under threat of prosecution for state and local election officials.

The dispute centers on actions by the Justice Department and Homeland Security, which sent letters to California election officials warning of potential criminal liability for officials who declined to investigate ballots linked to suspected noncitizens. Labor unions and civil rights groups, including the NAACP and the League of United Latin American Citizens, brought the case, arguing these letters amounted to intimidation.

Earlier, a three-judge panel of the 9th Circuit had granted the Justice Department's request to pause the restraining order. The panel initially suggested the government was likely to prevail in arguing that its requests and criminal investigations are core executive functions.

However, the full 9th Circuit's decision to vacate that ruling and order a rehearing means the district court's restrictions remain in place while the full court considers the matter. First Assistant U.S. Attorney Bill Essayli had previously stated that conducting criminal investigations is a core function of the executive branch.

The Trump administration contends that allowing illegal voting and halting investigative work could lead to prosecution for those involved, stating that "Americans deserve to have confidence in their elections." The Department of Justice has also announced that 63 people were charged with election crimes on Monday, with acting U.S. Deputy Attorney General Trent McCotter vowing to "continue pursuing every available legal avenue to protect the integrity of our elections and ensure federal law is enforced."

This development followed a separate Supreme Court rejection earlier on Monday of the Trump administration's attempt to require California to set aside mail ballots from approximately 20,000 registered voters flagged by federal officials as likely noncitizens. The administration had argued that once such ballots are commingled with lawful ones, they cannot be retrieved.

The DOJ has stated it has charged 195 illegal immigrants across 25 states with illegal voting and voter registration offenses in the past nine weeks, and 239 people with voting fraud offenses since President Trump returned to the White House.