Key facts about immigration data: What it can and can’t tell us about border policies

President Joe Biden was elected in 2020 after promising to reverse many of former President Donald Trump’s restrictive immigration policies, including some that limited people’s ability to apply for asylum at the southern U.S. border. But many Republicans, including those seeking to oust Biden in the November election, say his approach isn’t working and that the U.S. now has "open borders."

As evidence, Republicans cite the historically high number of migrant encounters border officials have recorded. And they compare that count with lower apprehension numbers under previous presidential administrations.

The Biden administration, in response, cites immigration declines after new policies were enacted as evidence that he’s got the problem under control.

But neither the attacks nor the defense tell the whole story. Although the immigration data cited is often accurate, the way it's presented or the inferences made are misleading or need context.

Here are key facts about immigration data that will help you better understand the oversimplified — or confusing — claims you’ll likely hear in ads and speeches preceding November’s election. 

We often hear that illegal immigration under Biden has reached record highs. There’s some truth to this, but there are also caveats. 

Data at a glance: Encounters under Biden have surpassed the record high 1.64 million apprehensions recorded in fiscal year 2000. It’s happened three times: 

• In fiscal year 2021, which began under Trump in October 2020 and ended in September 2021 with Biden in the White House, Border Patrol stopped migrants at the southern U.S. border 1.66 million times. 

• In fiscal year 2022, Border Patrol recorded 2.2 million encounters.

• In fiscal year 2023, encounters dropped slightly to 2 million. 

Still, "encounter" numbers aren’t exactly comparable with "apprehension" numbers. Border data under both Biden and Trump can’t be directly compared with data from previous administrations because of COVID-19 policy changes. 

Before the pandemic, claims about illegal border crossings generally involved only apprehension data. 

During the pandemic, the Trump and Biden administrations performed apprehensions under immigration law plus expulsions under Title 42, a public health policy, to stop people from entering the United States.

Starting in fiscal year 2020, U.S. Customs and Border Protection began reporting encounters, a combination of apprehensions and Title 42 expulsions. (Title 42 enforcement ended in May 2023.) So, the change in immigration data tracking makes it hard to fairly compare how many more people have come illegally during Biden’s presidency than during other administrations.

People expelled under the public health policy faced no legal consequences for repeatedly trying to enter the U.S. illegally. Immigration experts say that encouraged them to try over and over to cross. (Under immigration law, people can face legal penalties for repeat illegal entries.)

Comparing Biden-era staffing versus 2000: In 2000, there were fewer Border Patrol agents, and that likely made it easier to cross the border evading apprehension, the American Immigration Council, an immigrant-rights advocacy group, said in a 2022 report. Immigration officials estimate that 2 million people entered the U.S. without detection that year. In fiscal year 2021, the latest available data, about 390,000 people evaded detection.

So, even though there were more encounters in 2021 than apprehensions in 2000, immigration officials estimate that more people evaded detection in 2000 than in 2021.

What the data counts: Immigration data represents events, not people. If one person tries to enter the country three times and is stopped each time by border officials, for example, that equals three encounters, even if it’s the same person encountered.

Immigration data can give us a sense of the scale of migration, but it can’t tell us how many people crossed the border and now live here.

Florida Gov. Ron DeSantis misleadingly said in September that 6 million or 7 million people have "come illegally under Biden."

There were 7.8 million encounters nationwide under Biden as of October 2023. But this metric doesn’t confirm that 7.8 million people entered the United States. At least 2.5 million encounters ended in expulsions under the public health policy, and hundreds of thousands have been expelled under immigration law.

"There is no authoritative source on how many unauthorized immigrants have joined the U.S. population since President Biden took office," said Julia Gelatt, associate director of the U.S. immigration policy program at the Migration Policy Institute, a nonpartisan think tank.

President Joe Biden talks with U.S. Border Patrol agents as they walk Jan. 8, 2023. along a stretch of the U.S.-Mexico border in El Paso Texas. (AP)

The Biden administration has claimed that a "broken immigration system" resulting from decades of Congress not updating immigration laws, and increased global migration contribute to the high numbers of people arriving at the border.

In response, the Biden administration has created and expanded multiple immigration programs to deter and reduce illegal immigration. Among them:

• Humanitarian parole programs that allow hundreds of thousands of people from Afghanistan, Ukraine, Cuba, Venezuela, Nicaragua and Haiti to apply for a legal path to live and work in the U.S. for two-year periods. These are countries affected by wars and political instability.

• A smartphone app that lets people seeking asylum schedule appointments at official ports of entry. People who don’t do this must prove they unsuccessfully applied for asylum in another country before reaching the United States; otherwise, immigration officials will presume they are ineligible for asylum. 

• Negotiated agreements with Mexico for it to take certain deported non-Mexicans.

• Resumed deportation flights to Venezuela and other countries with which the U.S. has fraught diplomatic relations. 

To claim success, the administration has said that fewer people have shown up at the border after some of the policies were enacted.

"Since we created the new program the number of Venezuelans trying to enter America without going through a legal process has dropped dramatically," Biden said in January 2023, referring to a parole program for Venezuelans announced in October 2022.

But a closer look at the data shows the numbers ebb and flow.

Encounters dropped from nearly 22,000 in October 2022 to fewer than 7,000 in November 2022. They also dropped for the next few months, but then rose again to reach nearly 55,000 in September 2023. 

Immigration experts caution against attributing any immigration fluctuations to just one policy. 

New policies can lead to a pause in immigration "while migrants (and smugglers) consider what the changes mean, and then crossings again increase," Theresa Cardinal Brown, senior adviser for immigration and border policy at the Bipartisan Policy Center, said Dec. 19 on X, formerly Twitter.

A December 2023 report from the Bipartisan Policy Centers found that it’s hard to definitively conclude how single U.S. immigration policies over the past decade have influenced illegal immigration. The numbers alone don’t explain demographic changes or the factors that push people to leave their home countries. 

"Continued fluctuation in numbers of arrivals at the border is expected," the report said, "if there is no consistent immigration policy to address the ongoing migration crisis."

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