Since President Joe Biden took office in January 2021, United States Border Patrol has had about 4.7 million encounters with about three million individual illegal crossers along the Southwest border.

It is a chaotic mess. Border Patrol is overwhelmed. Migrants are dying en route or perishing at the hands of smugglers and cartels. But that chaos is already dramatically on the decline, as President Biden’s Jan. 5 immigration actions were the first major step in decades to get the border under control.

Biden announced that immigrants with U.S. sponsors from four major origin countries could apply to come legally to the United States on a status called humanitarian parole. And according to the January immigration figures released late last week, Biden’s plan is already working.

In December 2022, the last full month before humanitarian parole, Border Patrol had 84,176 encounters with migrants from those four countries which accounted for over 36 percent of all encounters that month at the U.S.-Mexico border. In January, the number had already dropped to 11,909—an 86 percent decline. As a result, overall U.S.-Mexico border encounters are down 42 percent.

This was similar to the decline in Ukrainians fleeing the Russian invasion showing up at the Southwest border in Spring 2022 after a similar program was announced. Their numbers dropped from 20,118 in April 2022 to 375 in May, a 98 percent reduction, after the Uniting for Ukraine parole program allowed them to come directly from abroad with a U.S. sponsor.

The Ukrainian program was the model for Biden’s Latin American humanitarian parole and it’s having similarly dramatic effects on improving border security.

The Biden administration isn’t solely responsible for that border chaos, as he inherited a legal immigration system decimated by his predecessor. Further, the labor market has recovered from the pandemic with unemployment at a low rate of 3.5 percent and private job openings reaching more than nine million for much of his administration.

On the other hand, it took the Biden administration about 18 months to fix the legal immigration system, and his administration sent mixed messages to the world about asylum and entry at the U.S. border.

But January 5, 2023 was a conceptual break from the past. The Biden administration announced a plan framed as additional immigration enforcement, but its most important aspects expand legal migration to the U.S. Using a power that Congress gave presidents in 1952 called humanitarian parole, Biden is allowing 30,000 migrants from Venezuela, Cuba, Nicaragua, and Haiti to legally come to the U.S. each month.

The migrants must have a U.S. sponsor and meet health and security standards. Once here, they receive a two-year residency permit—which could be extended—and they can apply for a work permit. They have almost no access to public benefits. If the numbers admitted under humanitarian parole are anything close to 30,000 people per month and the program lasts for the rest of his administration, this will be the single biggest immigration liberalization since the Immigration Act of 1965.

From a border security perspective, the goal of humanitarian parole is to incentivize migrants to apply from their home countries (or neighboring countries), get prior approval to enter, and then fly to the United States instead of paying smugglers to come to the border.

The Biden plan also requires anyone caught entering illegally from these countries be sent back to Mexico, but this aspect of the plan is less important because of the new legal option. Critics of the plan miss the forest for the trees; directly applying from their home countries means asylum seekers won’t have to spend thousands of dollars on being smuggled to the border or walking through brutal terrain like the Darien Gap, all while trying to avoid criminals, cartels, and corrupt officials along the way.

Still, humanitarian parole isn’t perfect. The numbers need to be greater than 30,000 per month, so residents of these countries aren’t discouraged from applying. The Latin American parolees need to have automatic work authorization without applying for a separate work permit (known as an EAD or employment authorization document). The Biden administration needs to reinstitute a $575 fee for each humanitarian parole application so the process doesn’t strain U.S. Citizenship and Immigration Services, an agency that relies on fees to process immigrants.

But most importantly, the Biden administration needs to extend humanitarian parole to every country south of Mexico with large numbers of migrants showing up at the border. It can start with adding Colombia, Ecuador, Guatemala, Honduras, and Peru, because they are the largest sending countries.

The Biden administration has turned a massive flow of illegal immigrants into a smaller flow of legal immigrants using a 71-year-old legal power granted to him by Congress. Migrants on humanitarian parole are legal migrants, lawfully allowed to live and work in the United States.

By extending humanitarian parole to other countries, increasing the numbers, attaching work authorization to parole, and reinstituting normal immigration fees, President Biden can be the first president to gain control of the border in generations.