Former Housing and Urban Development Secretary Julián Castro listed a series of actions he would take, as president, to end the migrant crisis at the U.S.-Mexico border.

Among them, he proposed an executive order to end President Donald Trump’s “zero tolerance” policy, and the repeal of “section 1325.” But the Trump administration ended the “zero tolerance” policy a year ago, under pressure regarding the separation of migrant children from their families.

The “zero tolerance” policy sought to end the practice of “catch and release,” under which Border Patrol agents would let illegal aliens go after they had crossed illegally into the country. But detaining illegal alien adults meant detaining children as well. Because of concerns for the children’s safety — and to discourage child smuggling — the government housed children in separate shelters. Under the Flores consent decree of 1997, it could not do so for more than 20 days.

However, the public outcry prompted the president to issue an executive order requiring illegal alien families to be detained together. That effectively ended the “zero tolerance” policy — though President Trump insisted there was still “zero tolerance” for illegal immigration.

The main reason children are held — including at the Homestead, Florida, shelter visited by Sen. Elizabeth Warren (D-MA) and other candidates — is that many of them arrive unaccompanied.

Section 1325 is the provision in the federal criminal code that makes crossing the border illegally a crime. Both Castro and Warren have called for decriminalizing illegal entry into the United States. (Update: Sen. Cory Booker (D-NJ) did so as well, on the debate stage.)

However, the children being sheltered at Homestead are not being held for punitive purposes, but because they cannot be released except into the care of a recognized sponsor. Repealing 1325 would likely encourage, not discourage, more illegal entry, including by children.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. He is also the co-author of How Trump Won: The Inside Story of a Revolution, which is available from Regnery. Follow him on Twitter at @joelpollak.