President Biden on Thursday implored lawmakers to enact permanent protections for immigrants without legal status who came to the United States as children, a path that would formalize their footing in a country they have known as home for years.

On Capitol Hill, though, nascent legislative efforts on the issue have become immediately intertwined with the increasing number of unaccompanied migrant children now arriving at the U.S. border — an escalating challenge that the Biden administration has struggled to manage.

As legislation establishing a pathway to citizenship for those known as “dreamers” easily cleared the House on Thursday, Senate Republicans have made it clear in early private negotiations that any measure that includes legalization would be difficult absent measures that would bolster border enforcement and tighten U.S. asylum laws, according to senior GOP and Democratic senators. At least 10 Republican senators are needed to pass most bills in the evenly split Senate.

Such changes are almost certainly antithetical to a White House that has already reversed several of President Donald Trump’s most restrictive immigration orders and an increasingly liberal Democratic caucus in Congress that is calling for more generous treatment of the young migrants who are fleeing to the United States, primarily from Central America.

“They’ve got a choice to make: Do they want to control the border and set the conditions for an immigration solution, or do they want to just say, ‘I was the opposite of Trump’?” Sen. Lindsey O. Graham (R-S.C.) said in an interview Thursday. “Right now, they’re on a glide path not to be able to get anything done on immigration and have a political nightmare on their hands.”

Biden said on Twitter that “it’s long past time Congress gives a path to citizenship for Dreamers . . . who strengthen our country and call our nation home” and he urged lawmakers to “come together to find long term solutions to our entire immigration system.” In a statement Thursday night, Biden said, “My Administration looks forward to working together with Congress to do the right thing for Dreamers and [Temporary Protected Status] holders who contribute so much to our country.”

Graham and Sen. Richard J. Durbin (D-Ill.) have introduced legislation that, like the House approved on a 228-to-197 vote Thursday, would create a pathway to citizenship for about 2.5 million immigrants who came to the United States as children.

But now, reflecting the views of many Republicans, Graham is suggesting changes to the current asylum process, such as revoking a 2008 anti-trafficking law that bars unaccompanied migrant children from being promptly deported unless they are from Mexico or Canada.

Graham is also calling for the reinstatement of the so-called “remain in Mexico” policy of the Trump administration that Biden quickly reversed, which requires asylum seekers to wait for their court hearings outside U.S. soil.

While the Biden administration has also kept in place a Trump-era order called Title 42 — which allows for rapid deportation of migrants to Mexico in an effort to contain the coronavirus pandemic — it has stopped the practice for teenagers and children.

“They’re going to have to start deporting unaccompanied minors back to their home countries or find a humane place to keep them in Mexico because if they don’t, the numbers are going to continue to grow,” Graham said. “But when you can get the numbers back down, and you got new policies in place, then that’s the time to sit down and talk.”

The debate on Capitol Hill is unfolding as the number of minors held in government custody along the southern border continues to spike. Administration officials said Thursday that roughly 4,500 children and teenagers were being held by Customs and Border Protection — far surpassing the previous high of 2,600 minors in June 2019.

Durbin, who chairs the powerful Senate Judiciary Committee and has negotiated multiple immigration overhaul efforts in the past, said Republicans have told him that asylum revisions must be discussed as part of discussions over “dreamer” protections. But doing so, Durbin said, would be better saved for later negotiations over a more comprehensive overhaul of immigration laws.

“This treatment of children is so sensitive and I’m not going to give on that. I doubt if my colleagues will,” Durbin said.

The White House has not said whether it would seek additional, emergency funding from Congress that would help house and care for the children arriving alone at the southern border, many with the goal of reuniting with a family member already in the United States.

Instead, it has pointed to Biden’s comprehensive immigration proposal as a potential panacea, considering it contains billions in additional funding to address the root causes of migration from Central America.

Efforts to pass a large-scale proposal has already proven difficult even in the Democratic-led House that can clear bills with a simple majority. Early tests of support for Biden’s bill have shown that it so far lacks the support to pass the chamber, according to people familiar with the counts. For that reason, House Speaker Nancy Pelosi (D-Calif.) and her leadership team have espoused a piecemeal approach to immigration that had previously been anathema to Democrats and advocates.

The American Dream and Promise Act would create a pathway for dreamers who are currently protected from deportation under the Deferred Action for Childhood Arrivals program.

Nine Republicans joined all Democrats to pass the bill. Three freshmen Republicans from Hispanic-heavy districts in California and Florida helped increase that GOP number since a vote in 2019.

The Farm Workforce Modernization Act, which also passed Thursday on a 247-to-174 vote, would also give agricultural workers a pathway for legalization.

Unlike with other party priorities such as gun restrictions, Senate Majority Leader Charles E. Schumer (D-N.Y.) has not committed to taking up the dreamer legislation immediately. Durbin had asked Schumer for some time and space to negotiate with Republicans on the matter, particularly because any immigration legislation would need GOP votes, according to a senior Democratic aide.

In response, Schumer told Durbin that he’d give him some time, but not too much, according to the aide, who spoke on the condition of anonymity to discuss private deliberations among senators.

The ongoing challenges at the border have not only complicated efforts by Democrats to enact immigration policy changes, but to craft a cohesive and coherent message pushing back against assertions from Republicans that the administration has lost control.

House Democrats received talking points from Pelosi’s office Saturday that had been passed along by the White House. In it were 16 bullet points broken that emphasized Democrats’ view that Biden’s immigration plan is the necessary fix for the border and that the blame should be pinned on Trump for dismantling key Obama-era provisions.

“We have a road map to reform our immigration system and are taking immediate action today to solve the problem,” read the email, obtained by The Washington Post. “Our approach makes us safer and is more effective but will take time to build out fully.”

But lawmakers familiar with the situation at the border say that Democrats must do more to educate each other and their base about the differences between how the Biden administration is housing children in comparison to the Trump administration.

“I would encourage, and I have encouraged, the Biden administration to get on TV more,” said Rep. Veronica Escobar (D-Tex.), who represents El Paso. “It’s always best to be as transparent as possible and to actually allow the media in and allow folks to answer questions because I think anything that’s shrouded in mystery is not good. That mystery breeds misinformation.”

Rep. Sylvia Garcia (D-Tex.) said she’s already seeing Texas Republicans argue that immigrants arriving at the border are spreading the coronavirus.

“We need some messaging on responding to the open borders bringing disease because that’s just not true,” she said. “The public needs to know that and I don’t think the administration is doing a good job right now to reassure people that that’s just not true.”

The congresswomen, along with others, are trying to succinctly explain the complex, highly partisan issue to voters whom Republicans target often.

Republicans have capitalized on the Democrats’ response to the border crisis, appearing the most united on the immigration issue in contrast with other popular items like the coronavirus bill that the opposition largely spearheaded.

“By granting amnesty to millions of illegal immigrants,” Rep. James Comer (R-Ky.) said, “Democrats are signaling to the world and human smugglers that our laws can be violated with little consequence.”

Nick Miroff and Mike DeBonis contributed to this report.