A majority of Senate Democrats called Thursday for Customs and Border Protection (CBP) acting Commissioner Mark Morgan to clarify earlier testimony where he affirmed all unaccompanied minors at the border are screened for signs of child trafficking.

The Democrats, in a letter led by Sens. Jacky Rosen (Nev.) and Kamala Harris (Calif.) questioned Morgan's assertions, citing a Trump administration policy of summary expulsions of undocumented immigrants at the border under new coronavirus prevention guidelines from the Centers for Disease Control and Prevention (CDC).

"In a recent hearing before the Senate Homeland Security and Governmental Affairs Committee (HSGAC), you stated under oath that CBP is screening all unaccompanied children it encounters at the border for human trafficking and other protection concerns," wrote the senators.

"That claim appears inconsistent with evidence indicating that CBP is summarily returning unaccompanied children to dangerous conditions without properly screening them in the case of children from Mexico and Canada, or designating them as unaccompanied and transferring them to the custody of the Office of Refugee Resettlement (ORR) within 72 hours," they added.

Unaccompanied minors are subject to safeguards under the Trafficking Victims Protection Reauthorization Act (TVPRA), which requires screening for signs of human trafficking of all minors caught by U.S. authorities illegally crossing land borders.

Immigration officials who find signs of trafficking are required to transfer potential victims to the custody of ORR, which can house the minors or find them foster care within the United States.

However, during the coronavirus pandemic, the number of minors transferred to ORR has fallen precipitously, according to official figures cited by the letter.

"In June alone, although CBP encountered over 1,650 unaccompanied children, it referred only 61, or less than four percent, of them to ORR. And operational guidance issued to CBP personnel concerning Title 42 expulsions fails to reference, much less require, screenings for unaccompanied children," wrote the senators.

Since March, border enforcement agencies have conducted what are known as Title 42 expulsions, the immediate return of foreign nationals to Canada or Mexico per the CDC guidelines.

Under normal circumstances, foreign nationals who enter the country without authorization are subject to Title 8 treatment, a lengthier process that doesn't take into account the sanitary emergency.

Morgan has called Title 42 expulsions "a game changer," as the number of immigrants in custody of CBP at any given time has plummeted under the CDC guidance.

But Democrats say the decrease in minors put through the regular screening process shows that statutory trafficking guidelines are being overlooked.

"The weight of this evidence causes grave concern," they write.

"Absent screenings and additional legal protections codified in the TVPRA, unaccompanied children — including the more than 2,000 unaccompanied children returned by [the Department of Homeland Security] under Title 42 — have no meaningful opportunity to pursue safety from the dangers they flee. Instead, these children undergo rapid expulsion to situations in Mexico and Central America where they face the prospect of trafficking and other severe harm — precisely the outcomes Congress intended to prevent with the TVPRA," they added.

The senators also cited reports that CBP has transferred some unaccompanied minors to custody of Immigration and Customs Enforcement, the agency tasked with interior immigration enforcement, rather than to ORR, which is housed within the Department of Health and Human Services.

Acting Homeland Security Secretary Chad Wolf testified before the committee Thursday, saying ORR is not currently capable of taking in more children, despite the fact that ORR is housing fewer than 1,000 migrant minors at the moment.

Representatives for CBP did not immediately return a request for comment on this story.

The senators slapped Morgan with a laundry list of questions and information requests, ranging from a reprisal of Rosen's questioning of him at the June 25 Senate hearing to requests for a full list of minors processed under Title 8 and Title 42.

"In view of the heightened risks facing these children, we request that you clarify your June 25 sworn testimony to HSGAC and provide written answers to the below questions no later than August 14. We also call upon CBP to fully adhere to all TVPRA requirements and to provide a report to our offices by August 21 detailing TVPRA compliance. The safety of these children depends on CBP’s fidelity to the TVPRA," the letter reads.

In addition to Harris and Rosen, the letter was signed by Democratic Sens. Richard Blumenthal (Conn.), Ed Markey (Mass), Bob Casey (Pa.), Catherine Cortez Masto (Nev.), Mazie Hirono (Hawaii), Kirsten Gillibrand (N.Y.), Dianne Feinstein (Calif.), Bob Menendez (N.J.), Cory Booker (N.J.), Amy Klobuchar (Minn.), Tammy Baldwin (Wis.), Elizabeth Warren (Mass.), Ron Wyden (Ore.), Martin Heinrich (N.M.), Tom Carper (Del.), Jeff Merkley (Ore.), Sheldon Whitehouse (R.I.), Tom Udall (N.M.), Dick Durbin (Ill.), Tina Smith (Minn.), Tammy Duckworth (Ill.), Chris Coons (Del.), Maggie Hassan (N.H.), Jack Reed (R.I.), Gary Peters (Mich.) and Patrick Leahy (Vt.).