Michael Bennet, Colorado’s senior senator, wants to protect non-citizens who have volunteered to serve in the U.S. military as the Trump administration gets tough of immigration policy.

Bennet is cosponsoring an amendment to shield the legal immigration status of those enrolled in the Military Accessions Vital to National Interest.

A backlog of background checks already has thrown up to 1,800 non-citizen recruits into risk of being discharged. Current law automatically forces out recruits after two years if they haven’t completed basic training, which can’t start until the background check is completed.

Those in the program are deemed to have skills critical to the military. He said the U.S, armed forces include more than 800 service members who are beneficiaries of the Obama administration’s Deferred Action for Childhood Arrivals. the so-called Dream Act.

The bill is the latest maneuver in Democrats’ struggle over immigration with President Trump, who announced last week that he would end DACA.which has shielded young non-citizens who were brought the U.S. as children, as long as they are bettering themselves.

All of the bill’s co-sponsors are Democrats: Dick Durbin of Illinois, Kamala Harris of California, Cory Booker of New Jersey, Dianne Feinstein of California, Bob Menendez of New Jersey, Jeff Merkley of Oregon, Jeanne Shaheen of New Hampshire and Mark Warner of Virginia.

Politico reported Tuesday night that the Democrats might not press too hard, however, to get the measure into the National Defense Authorization Act, the bipartisan bill that funds the military. They don’t want to anger Senate Armed Services Committee Chairman John McCain, the Republican from Arizona.

McCain has been willing to stand up to Trump on immigration matters and provided a crucial vote to defeat Republicans’ repeal and replace effort against President Obama’s Affordable Care Act in July.

If that’s the case, the amendment serves as a political reminder of those Trump hopes to deport.

“The men and women serving in our military through the MAVNI program are willing to risk their lives in defense of our country,” Bennet said in a statement. “We cannot allow bureaucracy to threaten these service members’ immigration status-that would be a disservice to the commitment and patriotism they have displayed in choosing to serve in our Armed Forces.”

Bennet’s amendment would require that those recruits to allowed to remain in the Armed Forces until the completion of background checks and security screenings, “regardless of how long the screenings take,” Bennet’s office said.