More than half the country's governors, citing security concerns, said they would refuse Syrian refugees

Obama addressed the issue at the end of a global summit in Turkey, saying he remains committed to accepting Syrian refugees, who he said face “rigorous screening and security checks.”

“Countries like Turkey, Lebanon and Jordan, which are already bearing an extraordinary burden, cannot be expected to do so alone,” he said. “Many of these refugees are the victims of terrorism themselves. That's what they're fleeing. Slamming the door in their faces would be a betrayal of our values.”

On Monday, Florida Gov. Rick Scott wrote to Ryan and Sen. Majority Leader Mitch McConnell (R-Ky.), asking for help to halt the planned resettlement of 425 Syrian refugees in his state.

“It is our understanding that the state does not have the authority to prevent the federal government from funding the relocation of these Syrian refugees to Florida even without state support,” Scott wrote. He called on Congress “to take immediate and aggressive action to prevent President Obama and his administration from using any federal tax dollars to fund the relocation … without an extensive evaluation of the risk these individuals may pose to our national security.”

Presidential candidate Sen. Ted Cruz (R-Texas) said Congress needs to ensure it is not “spending taxpayer dollars to import terrorism.” Sen. Lindsey Graham (R-S.C.) suggested “a timeout on bringing refugees into this country.” And Sen. Rand Paul (R-Ky.), another presidential hopeful, introduced legislation that would impose a 30-day wait on all new arrivals and suspend visas from countries at a “high risk of terrorism.”

But even those who support governors refusing Syrian refugees conceded that states do not have the authority to prevent the federal government from funding the relocation.

“They're making important political statements, but they have no legal control over this,” said Mark Krikorian, executive director of the conservative Center for Immigration Studies in Washington. He said there had been increasing “pushback against the State Department's heavy-handed attitude toward refugee resettlement” — not just from Syria, but also Muslim refugees from Iraq, Somalia, Yemen and other conflict zones.

“There is literally no way to screen refugees from the Middle East. There is no way to know who these people are. What are we going to do, call the Damascus police department?” Krikorian said.

His comments echoed FBI Assistant Director Michael Steinbach, who heads the bureau’s counter-terrorism division and testified before Congress in February that officials lack the databases to check Syrian refugees.

Refugee advocates disagree. They said refugees must pass repeated Homeland Security checks, including biometric screening and in-person interviews.

“These refugees are the most vetted, they go through more security screening than any arrivals to the United States. It's not like Europe. It's a different scenario,” said Kevin Appleby, who directs the Migration and Refugee Services Office of Migration and Refugee Policy at the U.S. Conference of Catholic Bishops, which resettles about 30% of refugees arriving in the U.S.

Appleby was particularly concerned about Michigan, which is home to one of the nation's largest Arab communities, including Syrians, and which would probably receive more as agencies attempt to reunify families.

“If states can start calling the shots on who they can take and when, it jeopardizes the whole program,” he said. “If we pull up stakes, the rest of the world will, and the terrorists win.”

Eleven states did not come out for or against the program, while 13 states that stood by admitting Syrian refugees included Alaska, Colorado, Connecticut, Delaware, Hawaii, Minnesota, Missouri, Montana, Pennsylvania, Vermont, Virginia and Washington.

“Washington will continue to be a state that welcomes those seeking refuge from persecution, regardless of where they come from or the religion they practice,” Gov. Jay Inslee said, dismissing “fear mongering” and “anti-refugee” comments by fellow governors as “of little value except to divide people and foment intolerance.”

Some members of Congress also bucked the backlash and supported Syrian refugees.

Rep. Adam Schiff (D-Burbank) acknowledged there is “some risk” associated with allowing refugees into the country, but cautioned against overreaction.

“To turn our backs on those escaping persecution, many of them religious minorities, runs counter to the proud and generous heritage of a United States that has always helped those in need during turbulent times,” Schiff said.