ÀÏ°ÄÃÅ¿ª½±½á¹û

In a to Secretary of Homeland Security Jeh Johnson yesterday, 10 Democratic senators, including all of the party's leaders, wrote: "Mothers and their children who have fled violence in their home countries should not be treated like criminals."

We couldn't agree more.

The letter – which was signed by Senate Majority Leader Harry Reid (D-Nev.), Judiciary Chairman Patrick Leahy (D-Vt.), Senate Majority Whip Richard J. Durbin (D-Ill.), and Sens. Charles E. Schumer (D-N.Y.) and Patty Murray (D-Wash.) – voiced unified opposition to the Obama administration's recent treatment of mothers and children fleeing violence in Central America.

In 2009, the administration wisely decided to stop detaining families at the T. Don Hutto Detention Center in Taylor, Texas, following years of ÀÏ°ÄÃÅ¿ª½±½á¹û litigation and other advocacy on the deplorable conditions of confinement and treatment of children at the facility. In the summer 2014, however, the administration reversed course and ramped up its efforts to detain families.

Virtually overnight the Department of Homeland Security (DHS) opened two new family detention facilities in Artesia, New Mexico, and Karnes County, Texas. And in November, ICE will start detaining families at a new detention facility in Dilley, Texas, which will have a 2,400-bed capacity and will be the single largest immigration detention facility in the nation. In just a few short months, family detention will jump from fewer than 100 beds as of May 2014 to nearly 4,000 in 2015.

That's a staggering increase of 3,900 percent in less than one year. That's not a typo.

Many of the moms and kids arriving in the United States have fled gang-related or severe domestic violence in Central America. Nonetheless, a recent prepared by the Mexican American Legal Defense and Educational Fund and Human Rights First documents allegations involving guards and staff at the detention facility in Karnes, Texas, engaged in sexual abuse and harassment of detained mothers.

History has shown that imprisoning families limits access to due process, harms the physical and mental health of children, undermines the family structure by stripping parents of their authority, and results in abuse of detainees. Moms and kids should not be locked up by our government. Rather they should be given mental health treatment and care appropriate for trauma survivors. Instead of scaling up family detention facilities, DHS should be investing in effective, humane, and cost-effective alternatives to institutional detention.

As the senators made clear in their letter to DHS, "The ongoing detention of women and children who have made credible claims that they have been victims of [domestic and sexual violence] is unacceptable."

Institutional detention must always be the last resort, not the first. The Senate Democrats understand this, and so should the Obama administration.

Learn more about immigrant children and other civil liberties issues: Sign up for breaking news alerts, , and .