Two Democratic senators and one Republican have written to Defense Secretary Jim Mattis, urging him to reverse the decision to send 21 military lawyers to the border to prosecute immigration cases.

In the letter to Mattis Thursday, the senators said that the JAGs (Judge Advocates General) lacked training in complex immigration law and their deployment to the border would add strain to an already overloaded military justice system.

"Pulling twenty-one trial counsel from military courtrooms to prosecute immigration cases is an inappropriate misapplication of military personnel. We urge you to maintain these resources within the military justice system," said the letter to Mattis from Sens. Joni Ernst, R-Iowa; Kirsten Gillibrand, D-New York; and Patrick Leahy, D-Vermont.

Ernst and Gillibrand are members of the Senate Armed Services Committee and Leahy is vice chairman of the Senate Appropriations Committee.

The senators wrote that the Department of Defense balked earlier this year at assigning more JAGs to cases of domestic violence and child abuse on military bases.

DoD said at the time that "expanding the duties of the JAG Corps without adding more personnel would risk "a significant reduction in the quality of services currently provided."

"Despite this response, the Defense Department is now sending twenty-one JAGs to the border," the letter said.

The decision to send JAGs to the border came on the same day that Pentagon officials said DoD was prepared to house up to 20,000 migrant children, and possibly their parents, on bases in Texas and Arkansas under a plan still in formulation by the Departments of Homeland Security (DHS) and Health and Human Services (HHS).

The bases under consideration were the Army's Fort Bliss, Goodfellow Air Force Base and Dyess Air Force Base in Texas; and Little Rock Air Force Base in Arkansas.

In a notification to Congress Wednesday night, the Pentagon said that officials at HHS asked whether beds could be provided at the bases "for occupancy as early as July through December 31, 2018."

Also on Wednesday at the Pentagon, Mattis told reporters that the military had experience in sheltering children and families at unused facilities.

"We'll see what they come in with," Mattis said. "We support DHS and right now this is their lead and we'll respond if requested."

Mattis noted that the military had in the past housed refugees.

"We have housed people thrown out of their homes by earthquakes and hurricanes," he said. "We do whatever is in the best interest of the country."

In 2014 during a surge at the border, about 7,000 migrants were temporarily housed by the Obama administration at the Army's Fort Sill in Oklahoma; Lackland Air Force Base in Texas; and Naval Base Ventura County in California.

HHS would be responsible for the care and feeding of the migrants should the current plan to use military bases be adopted.

In a tweet Friday, Trump again railed at Democrats for causing the problem.

"We must maintain a Strong Southern Border. We cannot allow our Country to be overrun by illegal immigrants as the Democrats tell their phony stories of sadness and grief, hoping it will help them in the elections," Trump said.

-- Richard Sisk can be reached at Richard.Sisk@Military.com.