WASHINGTON — The Biden administration is preparing to convert its immigrant family detention centers in South Texas into Ellis Island-style rapid-processing hubs that will screen migrant parents and children with a goal of releasing them into the United States within 72 hours, according to Department of Homeland Security draft plans obtained by The Washington Post.

The plans show the Biden administration is racing to absorb a growing number of migrants crossing the U.S.-Mexico border amid shortages of bed space and personnel. Republicans and some Democrats fear that relaxing detention policies will exacerbate a surge that is already straining the Biden administration.

Russell Hott, a senior official with Immigration and Customs Enforcement, notified staff of the rapid-processing plan in an email Thursday that said arrivals by unaccompanied minors and families this year “are expected to be the highest numbers observed in over 20 years.”

If U.S. border officials continue to take in more than 500 family members per day, the change in use to the family detention centers “may not be sufficient to keep pace with apprehensions,” Hott warned in his email, which was reviewed by The Post.

Individuals who cannot be housed in one of the rapid-processing centers may need to be placed in hotels, Hott wrote. MVM, an ICE contractor, will help transport the families to hotels if there is no longer capacity at the rapid-processing centers, he said, adding that the company plans to use hotels in McAllen and El Paso, Texas, and Phoenix.

“We welcome the change, because the detention of families – we never thought that was a good system or a good policy at all,” said Edna Yang, co-executive director of American Gateways, an immigration legal aid organization in Texas. “They shouldn’t be detained, and they should be given the opportunity to go before the immigration judge and be released in the community and not held like prisoners.”

The plans come as Republicans are criticizing President Biden for relaxing immigration policies, saying he could encourage more migration to the border.

“There is no question there’s a crisis at the border,” Rep. James Comer, R-Ky., said Thursday on Fox News. “It’s Joe Biden’s fault. Joe Biden has signaled to the world that he’s not going to take border security seriously.”

Transforming family detention amounts to a wholesale repudiation of not only Donald Trump’s policies but also Barack Obama’s and presents a significantly different vision of how to handle the fast-changing character of mass migration at the southern border.

For decades, single adults – particularly men – dominated the flows northward into the United States, but the number of families and minors traveling without their parents has increased substantially in recent years. Before the coronavirus pandemic, migrant families and unaccompanied minors were a majority of those taken into custody at the southwest border, a trend that more closely resembles refugee streams worldwide.

During the Obama and Trump administrations, most families were quickly released or deported. But some were held in dormitory-style facilities for weeks or months, if not longer, for immigration proceedings.

Advocates for these families have long said they are fleeing violence and poverty and shouldn’t be detained at all – a sentiment Biden echoed on the campaign trail last year.

“Children should be released from ICE detention with their parents immediately,” Biden wrote on Twitter in June. “This is pretty simple, and I can’t believe I have to say it: Families belong together.”

Six weeks into Biden’s presidency, advocates are frustrated that his administration has continued to detain families and expel them from the border under a public-health order. The number of detained family members more than doubled, from 228 adults and children before Biden took office to 476 last week, federal records show.

Although the tally is a fraction of the combined capacity of 3,300 people at three family residential centers, the uptick baffled child-welfare advocates who hoped that the detention centers would finally close. They noted that Biden and Alejandro Mayorkas, now the homeland security secretary, helped to expand use of these detention centers during the Obama era.

“There needs to be open expression of what they’re going to do with these facilities,” said Bridget Cambria, a lawyer representing migrant families in Pennsylvania.

“They shouldn’t detain families or children even for one second.”

ICE oversees three family residential centers for immigrants facing deportation: the 96-bed Berks Family Residential Center in Leesport, Pa., and a pair of larger facilities outside San Antonio, a 2,400-bed center in Dilley and an 839-bed center in Karnes City.

The Biden administration has said it is reviewing the way it uses family detention facilities and told a federal judge last week in a lawsuit over the detentions that the policies had not changed.

“A detention center is not where a family belongs,” Mayorkas told NBC News in an interview this week, hinting at the plans.

ICE emptied out the Berks center Feb. 26, releasing all 21 people there.

ICE confirmed that the facility is empty but would not say why.

Officials are considering turning Berks into a women-only center, a DHS official said, while Dilley and Karnes would serve as quick-release intake facilities that would screen migrant families, check their backgrounds and release them pending an immigration court hearing. Some would enroll in “alternatives to detention,” such as ankle-monitoring programs.

Families would undergo coronavirus testing, and nonprofits would then help them secure airplane or bus tickets to their final destinations in the United States, typically with relatives or friends.

The goal is to process and release 100 families per day, the plans show. Migrants who test positive for the coronavirus would be quarantined for 10 days.

In Texas, advocates said the region’s top immigration officials held an emergency conference call with them on Feb. 20 to discuss plans to transform the centers into shorter-term facilities.

Officials told them to prepare for more migrants to be released from Dilley and Karnes.

“It’s incredibly encouraging to hear a completely different philosophy and attitude for people coming into this country,” said Daniel Klein, board chairman for the Interfaith Welcome Coalition, who was on the call, first reported by the San Antonio Express-News.