After years of surging immigration from Central America, law enforcement in Texas’ Rio Grande Valley are finally seeing some relief, thanks in part to President Trump’s strong rhetoric.

“Words matter,” said Christopher Sabatini, an expert in Latin American affairs at Columbia University in New York City. “The rhetoric has mattered. There is a sense of fear that immigrant families, without legal status, without papers are going to be sent back down.”

That fear prompted a dramatic change in behavior among illegal immigrants that few predicted. For three years, a flood of unaccompanied children, women and families made the hazardous trek north from Hondurans, El Salvador and Guatemala, through Mexico to the U.S. Border. Now they are not coming.

“We’re at a trickle,” said Chris Cabrera, with the National Border Council. “It hasn’t stopped but it’s slowed considerably that we’re at a point where we have empty cells now.”

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That added bed space is allowing Immigration and Customs Enforcement to hold immigrants longer. Previously, Central American immigrants turned themselves in, claimed asylum and were released.

In most cases, the Obama Administration accommodated the claim by placing the applicant on a court docket with a two- to three-year waiting list. In the meantime, most illegal immigrants were free to work while living with relatives. Some set down roots by getting married or having American-born children.

President Trump promised to end that ’catch and release’ policy, saying “anyone who illegally crosses the border will be detained until they are removed out of our country.”

Apparently that message got through thousands of miles away.

“Since January, we have seen a significant decrease in traffic to the point we’re averaging about 150 alien apprehensions a day,” down from as many as 1,000 a day, according to Deputy Chief Raul Ortiz of the Rio Grande Border Patrol Sector. “A big part of the decrease, I think, has to do with a lot of the discussion about the buildup of infrastructure on the southwest border, more agents along the border and some of the message making its way down to those host countries.”

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And with traffic down, more enforcement means higher smuggling costs, detained immigrants tell the Border Patrol.

“If you think that you are not going to be able to stay with relatives, you are not going to spend $8 to $9,000 to cross just to get caught and sent back,” said Border Patrol agent Marlene Castro while overlooking the once busy Rio Grande.

Border Patrol numbers tell the story. Since the election, apprehensions have fallen every month, from 15,000 families and unaccompanied minors in November to just over 1,000 today.

Cabrera believes media reports surrounding ICE arrests, the proposed wall and the president’s vows to enforce the law scared many illegal immigrants into staying home.

“The media has a big say in what happens,” he said. “They put that out there and people come or don’t come, depending on what they say.”

The same holds true, he said, of President Obama. Though his administration also vowed to deport most illegal immigrants and even produced an expensive ad campaign in Central America urging residents to stay home, the headlines told a different story – of immigrants getting temporary amnesty and freedom from custody for those claiming asylum. By contrast, President Trump hasn’t actually done much.

“Without any real concrete changes in policies, without any real tightening of the border wall, without any of the $1.5 billion worth of increased funding yet for Homeland Security and the border guard, we are seeing the numbers that it is having an effect on people’s calculation of the risk of crossing the border illegally,” said Sabatini.

The administration has elaborate plans to strengthen both the border and the court system to diminish the ‘pull’ factors in illegal immigration.

So far, the Department of Justice has reassigned 25 judges from the interior to the border to help streamline the process and keep immigrants in custody until their asylum claims are completed.