Tracking undocumented immigrants can be challenging, making the task of attributing the decline to any one factor equally difficult. In January, my colleague Russell Berman noted a couple of factors that may have played a role, including the Great Recession, which discouraged the flow of migrants into the United States, as well as a declining birth rate and improving economy in Mexico.

To be clear, there are caveats to the report, and they’re important to understand when reviewing the flow of undocumented immigration as a whole. For example, while there has been a decrease in the number of immigrants from Mexico, the number from Central America has increased. Most recently, American officials have expressed concerns because the number is beginning to creep up again.

U.S. Customs and Border Protection released figures showing a surge in the number of immigrants—many of whom were from El Salvador, Guatemala, and Honduras—who were apprehended along the southwest border. Still, undocumented immigrants make up less of the U.S. population at 3.5 percent than they did in 2007 at 4 percent.

ANSWER

Still, that’s a considerable number of undocumented immigrants residing in the United States. The government needs to take a more aggressive enforcement strategy and deport those who are in the country illegally.

QUESTION

How effective would deportation really be? Early on, the Obama administration stepped up enforcement. In fact, President Obama deported more people than his predecessors, Bill Clinton and George W. Bush, according to data from the Department of Homeland Security. The department details the number of removals and returns, dating back to 1892.

Historically, returns—defined as “the confirmed movement of an inadmissible or deportable alien out of the United States not based on an order of removal”—make up the larger share compared with removals, but in recent years, that trend has been reversed. In 2013, more than 438,000 people were removed compared to the more than 178,000 returns. In 2014, 414,481 people were deported—a small decrease from the previous year but still historically very significant. And yet, it was also the year that saw the sudden surge of unaccompanied minors at the U.S.-Mexico border. Homeland Security Secretary Jeh Johnson announced a strategy that included collaborating with Mexico, Guatemala, Honduras, and El Salvador.

Deportations are also politically tricky. Recently, the Department of Homeland Security conducted removal raids that quickly became a point of contention between Democratic lawmakers and the White House. U.S. officials said the operation—launched in the hopes of preventing another surge—was meant to send a message to Central American migrants looking to make the journey.

But Democratic members of Congress—already skeptical of deportation—want to see migrants treated as refugees, not wrongdoers, as many are fleeing dangerous conditions. To this end, in January the Obama administration announced a refugee resettlement program with processing centers in Latin America to stanch the flow of immigrants crossing the U.S. border illegally. The program is still separate from deportations, but it implicitly acknowledges that removals are not the answer—or at least not the only answer.