The details of the inquiry remain unclear, but it is one of the rare instances in which a Trump ally or appointee has been investigated for potential wrongdoing during the president’s second term.
Corey Lewandowski, who served as President Trump’s first campaign manager a decade ago, worked closely with Kristi Noem, the former homeland security secretary.
The ruling largely blocked homeland security agents from carrying out field interviews in nine states, including California, as part of a sprawling effort to find noncitizens registered to vote.