An Obama-era judge is attempting to challenge the Trump administration’s decision to deport suspected gang members from Venezuela. Judge James Boasberg issued a temporary restraining order last weekend and is now requesting flight records from the administration.

The deportation of more than 200 Venezuelans had already begun by the time the judge’s written order appeared in court records. Flights carrying deportees had reached Honduras and continued on to El Salvador as part of a regional security arrangement.

Boasberg, who previously served under President George W. Bush in a local D.C. court, is now warning the administration of possible consequences for carrying out the removals. However, he has yet to specify what action he might take.

The Trump administration invoked the Alien Enemies Act, an 18th-century law allowing the president to expel non-citizens linked to hostile foreign powers. DOJ attorneys argued in court that not all the deportees fell under the judge’s jurisdiction and that national security concerns justified the removals.

President Trump responded on social media, calling Boasberg a leftist activist and suggesting impeachment. The chief justice of the Supreme Court weighed in, stating that appeals are the proper path for challenging a ruling, not impeachment.

Boasberg claimed he needed flight information to confirm whether his directives had been violated. The DOJ said disclosing such information would jeopardize security operations.

The deported individuals are now being held in El Salvador at a high-security facility used for regional gang control.