“We’ll be releasing gang members. We’ll be releasing individuals convicted of domestic violence and drug crimes,” said Matthew Albence, deputy director of Immigration and Customs Enforcement. “We will not be able to respond to as many calls as we do today. And in fact, in many of these calls, we’re going to tell them, ‘Just release them,’ because we have no choice.”

Democrats point out that more than a quarter of current ICE detainees are not subject to mandatory detention under the law.

Both Republicans and Democrats are citing competing data to claim that the new budget proposal advances their goals. Here’s what the plan really says:

Why has the border wall taken a back seat?

Months of brinkmanship between Congress and the White House over the border wall have distracted from the issue of detention, which has now reached a breaking point, with the authorities being urged by the White House to arrest more immigrants than they can currently afford to detain.

With little support for a robust border wall on either side of the aisle within Congress, Republicans and Democrats have moved on to detention, which is also expensive, and has implications for recent border crossers as well as immigrants with firmly established roots in the United States.

Why are so many people being detained?

Mr. Trump’s strict enforcement agenda has pushed the population of detained immigrants to the highest levels in history, with the authorities sweeping into immigrant-heavy locales to arrest vast numbers of the undocumented, as well as immigrants who have violated the terms of their visas (usually through criminal convictions), making them deportable.