Rauner previously has supported a pause in accepting Syrian refugees out of fears he expressed of potential immigration of terrorists supporting the radical Islamic State following the November 2015 attacks in Paris.
But following a tumultuous weekend featuring the detainment of legal residents and protests at some of the nation's airports, including O'Hare International Airport, the Rauner administration said the courts should be the arbiter.
“The governor has been supportive of tightening the vetting process for Syrian refugees because of ISIS attempts to infiltrate refugee flows -- but he's opposed to immigration bans that target any specific religion,” a statement from Rauner’s office said.
The Rauner administration statement did not specifically address provisions of Trump’s executive order that favored immigration of Christians and others over Muslims.
“Serious concerns about the executive order have been raised. We urge swift resolution of these concerns through the courts to ensure we are a nation that is both secure and welcoming of immigrants and refugees,” the statement from Rauner’s office said.
Several federal courts temporarily blocked provisions of Trump’s executive order, including bans on the entry of legal residents holding green cards from the seven Middle East nations the president targeted, including Syria.
Rauner was among three governors invited to this weekend’s California gathering of the donor network headed by conservative billionaire industrialist Charles Koch, chairman and CEO of Koch Industries.
A Rauner spokeswoman confirmed the governor's attendance, saying the event was "an opportunity to talk to about the advancements Illinois has made on criminal justice reform."
The Washington Post reported the network plans to spend as much as $400 million on policy and political campaigns in the next election cycle. The network is made up of about 700 donors who give a minimum of $100,000 a year.
In November 2015, Rauner and governors from more than half the states sought a moratorium on resettling Syrian refugees after a series of terrorist attacks in Paris. A Syrian passport linked to the siege turned out to be fake.
Between Rauner's announcement and mid-December, 871 Syrians started new lives in Illinois, according to the Refugee Processing Center, which is run by the State Department.
Rauner last year said his office was looking into its legal options and wanted a review of the U.S. Department of Homeland Security's acceptance and security processes. His office would not detail what action Rauner has taken since then.
The federal government administers refugee resettlement programs in cities across the country, but states play a supportive role, offering social services and housing. The federal screening process takes 18 to 24 months and involves multiple agencies.
A ruling from the 7th U.S. Circuit Court of Appeals in Chicago bolstered the department's lead role. A unanimous three-judge panel in October held that Indiana Gov. Mike Pence, now the vice president, had no authority to block Syrian refugees from being placed in his state.