The Senate will consider new rigorous screening procedures for Syrian and Iraqi refugees seeking to enter the United States -- as national security looms large for voters in an election year.
Propelled by the Islamic State group's attacks in Paris, the GOP-backed legislation raced through the House last November with 289 votes. That veto-proof margin included 47 Democrats despite the Obama administration's opposition to the measure.
The legislation will have a much harder time making it through the Senate in the week ahead.
Majority Leader Mitch McConnell, R-Ky., needs at least six Democrats to join all 54 Republicans to approve a motion clearing the bill for final passage in the 100-member chamber.
The Senate's top Democrat, Harry Reid of Nevada, said last year that was not going to happen. Even if it did, President Obama has pledged to veto the bill if it got to him.
The upshot may be more of the same on Capitol Hill: a war of words, with Republicans blasting Obama for failing to do what they see as necessary to secure the United States and Democrats accusing the GOP of fearmongering to score points with voters.
Here are some of the key points to know about the Syrian-Iraqi refugee legislation:
WHAT THE HOUSE BILL DOES
The Islamic State controls territory in Syria and Iraq. As a result of the extremists' harsh, uncompromising rule, people in those areas have tried to flee and make it to the United States. The House-passed American Security Against Foreign Enemies Act is rooted in concerns the current process of screening refugee is inadequate and could allow a terrorist to be admitted into the country.
The legislation would order FBI background checks for Syrian and Iraqi refugees and require that the FBI, Homeland Security Department and the director of National Intelligence certify that each refugee is not a security threat. The bill's requirements would effectively suspend admissions of Syrian and Iraqi refugees.
Republicans pointed to the arrest this month of two Iraqi refugees with suspected links to terrorism as one more example of the flawed vetting system.
Over the past few months, voters' concerns about terroris have surged and their confidence in the government's ability to defeat IS and other extremist groups has plummeted, according to a national survey conducted in December by the Pew Research Center.
"I think there's a sense we need to do everything we can to demonstrate we take seriously the responsibility to protect the country," Republican Sen. John Thune of South Dakota, a member of the GOP leadership, said last week at a GOP retreat in Baltimore.
A PROMISE TO VETO
The White House said Obama would veto the House bill. The legislation "would provide no meaningful additional security for the American people," it said in a Nov. 18 statement.
Refugees of all nationalities, including Syrians and Iraqis, already face a demanding screening process. And the legislation "would unacceptably hamper our efforts to assist some of the most vulnerable people in the world," the statement also said. The White House said more than 2,100 Syrian refugees have been admitted to the U.S. since 2001 and not one has been arrested or deported on terrorism-related grounds.
`DON'T WORRY, IT WON'T GET PASSED'
After the House passed the bill Nov. 19, Reid predicted it would die in the Senate. "Don't worry, it won't get passed," the Senate minority leader told reporters.
A final decision on how the Democrats will proceed is expected on Wednesday at their weekly caucus meeting.
Without support from Democrats, the math doesn't work for McConnell. Beyond the half-dozen Democrats he needs to ultimately get a full vote on the legislation, he need 13 more Democrats to reach a veto-proof tally.
The House vote demonstrated that opposing the legislation can be dicey for Democrats facing tight 2016 elections. Before the vote, White House aides went to the Capitol to win over Democrats. Rep. Sean Patrick Maloney, D-N.Y., told them, in a forceful exchange, that voting "no" could hurt Democrats at the polls.
Sen. Jack Reed, D-R.I., said other steps should include addressing illegal immigration more broadly and barring the sale of guns to people on federal terrorism watch lists -- a move the Senate recently rejected.
AP congressional correspondent Erica Werner contributed to this report.