CHICAGO (Reuters) - Indiana Governor Mike Pence, the Republican nominee for U.S. vice president, lost another round in federal court on Monday in his bid to keep refugees fleeing Syria’s civil war from resettling in his state.

Republican vice presidential nominee Indiana Governor Mike Pence speaks at the Republican National Convention in Cleveland, Ohio, U.S. July 20, 2016. REUTERS/Jonathan Ernst

The 7th U.S. Circuit Court of Appeals in Chicago affirmed a lower-court ruling that Pence’s order seeking to bar state agencies from helping the resettlement of Syrian immigrants discriminates against the refugees based on their national origin.

The setback for Pence comes a day before he is scheduled to debate the Democratic vice presidential nominee, Virginia Governor Tim Kaine, on national television.

Pence was among more than 25 U.S. governors, mostly Republicans, who urged President Barack Obama to stop resettling refugees fleeing Syria’s civil war after November attacks by extremists in Paris that killed 130.

Critics of the resettlement program have argued that it leaves the United States vulnerable to infiltration by militants from Islamic State, also known as ISIS, which has seized vast swaths of territory in Syria and Iraq and claimed responsibility for attacks on civilians in Paris and elsewhere.

But Appeals Court Judge Richard Posner, writing for the three-judge panel that sided unanimously against Pence, said the governor’s assertions of a national security threat were presented “without evidence” and amounted to “nightmare speculation.”

All three appellate panel members are Republican appointees, including Judge Diane Sykes, who Pence’s running mate, Donald Trump, has said he would nominate to the U.S. Supreme Court if he wins the Nov. 8 presidential election.

A Pence spokeswoman, Kara Brooks, said the FBI and U.S. Homeland Security Department have acknowledged “security gaps” in screening of Syrian refugees. She also quoted a State Department spokesman who said last month that he “‘wouldn’t debate the fact that there’s the potential for ISIS terrorists to try to insert themselves’ into the refugee program.”

Pence’s order was blocked by a U.S. district judge in February after a court challenge brought by the American Civil Liberties Union (ACLU), and he appealed.

The ACLU welcomed the court’s ruling on Monday as upholding the group’s position that the governor “may not constitutionally or legally discriminate against a particular nationality of refugees that are extensively vetted by the federal government.”

Indiana has accepted 150 Syrian immigrants between Oct. 1, 2015, and Aug. 31, 2016, accounting for about 9 percent of all refugee arrivals in the state during that period, according to the State Department.