President Barack Obama. Thomson Reuters Turning on President Barack Obama and other Democratic leaders, a significant chunk of the House Democratic caucus sided with Republicans in an effort to effectively stifle the flow of Syrian refugees into the US.

On Thursday, 47 House Democrats voted in favor of a bill authored by Rep. Mike McCaul (R-Texas). The bill passed, 289-137, giving it just enough to overcome a threatened veto from President Barack Obama.

The legislation bars Iraqi and Syrian refugees from being admitted to the US until the FBI director and the Director of National Intelligence certify to Congress that each refugee does not pose a national-security threat.

The bill's passage comes less than a week after the Paris terror attacks, which left 129 dead and hundreds more injured. One of the suspected attackers was found with a refugee passport, though its authenticity has not been confirmed.

Following the attacks, more than 30 governors and a number of mayors came out against Obama's plan to resettle up to 10,000 Syrian refugees over the next fiscal year.

The Obama administration lobbied Democrats hard on Thursday, to no avail. In a closed-door meeting, White House Chief of Staff Denis McDonough and Secretary of Homeland Security Jeh Johnson tried to convince skeptical Democrats.

But a Democratic source familiar with the meeting told Business Insider that many Democrats came away from the presentation more in favor of the GOP-led bill. The White House's presentation was heavily focused on process, and Democrats feared it would not translate into credible arguments they could make to skeptical constituents.

Indeed, several Democratic sources told Business Insider on Thursday that House Democrats feared the poor optics of voting against a bill strengthening barriers for refugee resettlement specifically from Iraq and Syria. A Bloomberg Politics survey released Wednesday found that 53% of Americans favored barring any Syrian refugees from entering the US.

A Syrian refugee carries a bag she received as aid for the winter from the UN refugee agency (UNHCR) in Tripoli, northern Lebanon. Thomson Reuters However, the bill passed with less Democratic support than leadership had feared — which, before the vote, was anywhere up to 100 defections.

And Senate Democrats were quick to say Thursday that the legislation wouldn't pass through that chamber. A Senate Democratic aide told Business Insider that the caucus "doesn't think there's an issue with the refugee process."

Obama, after the White House issued a veto threat late Wednesday, said the legislation would provide unnecessary barriers for refugees while doing little to make the US safer.

"The idea that somehow they pose a more significant threat than all the tourists who pour into the United States every single day just doesn’t jibe with reality," he said after a bilateral meeting with Canadian Prime Minister Justin Trudeau.

Many experts contend that attaining refugee status is one of the most difficult ways for foreign nationals to travel to the US.

"It is extremely unlikely that someone who is a terrorist will be sent through the refugee resettlement program," Greg Chen, director of advocacy at the American Immigration Lawyers Association, told Business Insider on Monday.

"It takes a great deal of time, and it wouldn't make sense for someone who is a terrorist to go through that process. There are going to be easier ways for a terrorist to try to infiltrate, rather than going through the refugee resettlement program."