The American Civil Liberties Union and other migrant advocacy groups are fed up with President Biden for continuing some of the controversial immigration practices used by President Trump.

Why it matters: With the president approaching his 100th day in office, the situation at the southern border has become his administration's biggest problem and threatens the Democrats' chances in the pivotal 2022 midterms.

What we're hearing: Administration lawyers have been slow-walking negotiations with the ACLU trying to get the group to hold off on a lawsuit that could dismiss Title 42, sources familiar with the talks tell Axios.

• Trump enacted the controversial policy in March 2020, allowing officials to rapidly return people who illegally crossed the border back to Mexico, including asylum seekers.
• Biden quietly continued it in January, claiming it was necessary to limit the spread of coronavirus.
• Yet the White House has also consistently publicly proclaimed its policy is to expel families, and officials have said they’re working with Mexico to expand space for more migrant families — which ACLU lawyers have privately said is frustrating.

Biden's also condemned Trump's hardline Migration Protection Protocols (MPP) — which sent thousands of asylum seekers back to Mexico while U.S. courts processed their claims.

• While Biden promised to end MPP on Day 1, his administration continues to expel single adults and some families without due process under Title 42.
• Many are being returned to some of the same areas they were sent under MPP.
• “In a lot of ways, it's 'Remain in Mexico' by another name,” Dylan Corbett, founding director of the HOPE Border Institute, an El Paso nonprofit, told Axios.

The president has yet to reunite a single family separated under the Trump administration.

• The Biden team says that is in large part due to the lack of process used by the Trump administration as it separated the families.
• That forced the new team to manually dig through thousands of government files, trying to match separated parents and children.

What they're saying: "We put our Title 42 case for families on temporary hold in exchange for good faith promise to negotiate," ACLU lawyer Lee Gelernt said in a March 25 tweet. "But POTUS JUST said his hope is that U.S. wants to expel ALL families if Mexico will allow them. Then litigation may be only choice."

• On Monday, the ACLU issued another extension in its lawsuit against the administration. The next deadline will be April 22.
• “We are not pleased with the pace of negotiations or the public statements from the administration that they are not looking to end Title 42 anytime soon,” Gelernt told Axios.

On the other hand: The Biden administration is rapidly opening up temporary shelters for families and kids, including an $86 million contract for hotel rooms.

• It's transforming camps and convention centers into temporary holding areas for minors.
• After receiving backlash from advocates, it has yet to reopen a massive shelter in Homestead, Florida.
• The government pays to keep it on "warm status" — perpetually ready to be opened immediately.

The White House did not return requests for comment.