Eleven U.S. senators, including five running to be the Democratic nominee for president in 2020, say they oppose a proposal by the Trump administration to restore authority to the Department of Homeland Security to collect DNA samples from migrants that have been detained after entering the U.S.

In their Oct. 30 letter to Attorney General Robert Barr and Acting Homeland Security Secretary Kevin McAleenan, the senators charge that “the real rationale for this new policy appears to be the Trump administration’s unending desire to vilify and stigmatize immigrants, and to erect any and all possible obstacles to immigration to the United States.”

The five senators campaigning for the Democratic presidential nomination that signed the letter are Cory Booker (N.J.), Kamala Harris (Calif.), Amy Klobuchar (Minn.), Bernie Sanders (I-Vt.), and Elizabeth Warren (Mass.).

The Justice Department earlier this month published a proposed rule that would allow relevant federal agencies, including DHS, to “collect DNA samples from individuals who are arrested, facing charges, or convicted or from non-United States persons who are detained under the authority of the United States.”

The proposed rule follows a 2005 law permitting the collection of DNA from migrant detainees, but in 2010 then Homeland Security Secretary Janet Napolitano was granted an exception from the law by the Justice Department due to resource limitations and the challenges associated with collecting the samples.

But the Justice Department in the Oct. 22 notice in the Federal Register said that it is now cheaper and easier to do DNA sample collection than before, pointing out that “it is now carried out as a routine booking measure, parallel to fingerprinting, by Federal agencies on a government-wide basis.”

In their letter, the senators quote a March 29 letter from former Homeland Security Secretary Kirstjen Nielsen seeking emergency funding because “’agents and officers are stretched too thin’” and the department “faced a ‘system-wide meltdown.’”

The senators say “That state of affairs described by the Secretary of Homeland Security cannot be squared with the proposed rule’s assertion that there are no longer ‘operational exigencies or resource limitations’ precluding widespread DNA collection.”

The letter was also signed by Democratic Sens. Michael Bennet (Colo.), Richard Blumenthal (Conn.), Mazie Hirono (Hawaii), Edward Markey (Mass.), Patty Murray (Wash.), and Patrick Leahy (Vt.).