Senate Republicans on Tuesday signaled they are willing to hold up House-passed legislation to provide a citizenship path for millions of undocumented immigrants, including those brought to the U.S. as children, amid high levels of migration — previewing another congressional showdown on immigration.

During a Senate Judiciary Committee hearing on the bill, ranking member Charles E. Grassley, R-Iowa, said he sees “justice” for immigrants who came to the country when they were children, known as “”Dreamers,” “as a legitimate thing to do.”

However, he also said any legislation providing legal status to these individuals must come with measures boosting border security and immigration enforcement. He cited current levels of high migration at the southwest border, a point echoed by several of his Republican colleagues throughout the hearing.

“If we want to provide legal status for Dreamers, we must secure our border, so that we don’t find ourselves in the same situation again, 20 or 30 years from now. Unfortunately, the administration doesn’t appear to be serious about doing that, and the bills we’re discussing today don’t even attempt to do that,” Grassley said.

Sen. John Cornyn, R-Texas, also took issue with the broader scope of legislation the House passed in March to establish an earned path to citizenship for millions of immigrants with temporary protections, saying it is “politically unlikely” the Senate would pass it.

A narrower version of the bill introduced in the Senate also would cover recipients of the Deferred Action for Childhood Arrivals program, the Obama-era program providing temporary protections for undocumented immigrants who came to the U.S. when they were children. The House bill central to the hearing, however, also covers immigrants who came to the U.S. as adults now living under temporary protections for designated countries in crisis.

“Radical policies that reward illegal immigration will not pass the Senate, and it’s unfair for the DACA recipients to tie their fate to such ill-considered legislation,” Cornyn said. “A clean, bipartisan bill is the only path forward.”

Not mincing words on the Senate floor the day before, Cornyn said the House measure “stands zero chance of being passed by the Senate” and accused his Democratic colleagues of holding a hearing on a “dead-on-arrival bill.”

The Senate hearing was held on the nine-year anniversary of the creation of DACA, which President Barack Obama announced from the Rose Garden in June 2012.

The panel’s Democrats invited Leon Rodriguez, former U.S. Citizenship and Immigration Services director under the Obama administration, and two health care workers living with DACA and temporary protected status. The committee Republicans invited Joseph Edlow, a USCIS leader under the Trump administration, and Michelle Root, whose daughter Sarah was killed by a drunk driver who was undocumented.

Immigrant advocates commemorated the anniversary by demonstrating near the White House to push the Biden administration and congressional Democrats to act.

“Democrats cannot allow Republicans to keep progress from happening this year,” Greisa Martinez Rosas, executive director of United We Dream, said in a statement Tuesday. “As we celebrate nine years of our power in winning and protecting DACA, we must remember that DACA is temporary and our communities need and deserve permanency through a pathway to citizenship.”

Skeptical that a Dreamer bill could earn the 60 Senate votes needed to move forward, some advocates have pushed Democrats to include citizenship provisions in a reconciliation measure, which could pass with a simple majority.

[Bipartisan immigration talks thwarted by escalating migration]

Still, lawmakers have attempted to engage in regular bipartisan immigration talks, but so far they remain at an impasse. Recent increases in migration toward the U.S.-Mexico border, where border agents encountered more than 180,000 migrants last month, have threatened to derail any efforts to revise other areas of the immigration system.

Judiciary Chairman Richard J. Durbin, D-Ill., who has championed legislative efforts to legalize Dreamers for decades, indicated at Tuesday’s hearing he would be willing to work with Republicans on some of their demands related to the border.

“I’ve accepted Sen. Cornyn’s invitation — rather, challenge, I’ll call it — to act on the southern border as part of any conversation that we have about any aspect of immigration,” Durbin said. “I think that is a good faith effort to try to find some common ground on a very challenging situation.”

[Legal threats loom over Senate hearing on Dreamers]

Still, some committee Republicans suggested they would be unlikely to vote for any legislation providing legal status to the undocumented population while migration to the border is high.

Sen. Ted Cruz, R-Texas, slammed the legislation as “amnesty,” while Sen. John Kennedy, R-La., called the timing bad.

“The house is on fire, and we’re discussing new tires for the fire truck,” Kennedy said.

Sen. Alex Padilla, D-Calif., chairman of the committee’s immigration panel, dismissed the analogy.

“The reality is when the house is on fire, let’s not forget the people who are inside the house,” he said.

Durbin struck a conciliatory tone as the three-hour hearing closed.

“If you were wondering at the introduction why this measure has been pending for 20 years and witnessed this hearing, you have some indication why,” Durbin said. “There clearly are differences of opinion on immigration policy. It is interesting that a nation of immigrants has such mixed feelings about the next immigrant to come into this country.”