If you’re interested in the real reason, this is not quite true, although I would not disagree that he thought the extra deterrent would be a bonus.
This was not actually a policy. This was a side effect of a different policy. The policy was zero tolerance on criminal immigration law. That means, if an adult crosses the border illegally, they committed a crime and must be arrested for said crime. That part isn’t actually new, Trump just directed them to enforce the law. That’s where the issue comes in. When an adult male goes to jail, such as if I were to get a DUI with my kid in the car, I’m not allowed to take a kid in with me to jail. It doesn’t matter if they’ll be left alone with no one to care for them. No matter what, arrestees can not bring their kids to jail, ever.
So in this situation, the parent is arrested and charged with a crime, and the kids are held until a guardian can be located. And guess what? Many from Mexico or El Salvador actually don’t want to come up to the US and get their kids, if such a person even exists. The Obama admin built these “cages” for that reason. But, they didn’t enforce the law as much, so they were not used so often. They did build them and they did put kids in them though.
The policy absolutely was intended as a deterrence:
the heads of the three major immigration agencies wrote to their boss, Secretary of Homeland Security Kirstjen Nielsen, to present her with three options for how to step up immigration enforcement at the border. They recommended “Option 3” — prosecuting every adult who crossed the border illegally, including those who came with their children — because it would “have the greatest impact on current flows.”[2]
> No matter what, arrestees can not bring their kids to jail, ever.
And yet through some miracle they reversed this policy and issued a new executive order reversing the "zero-tolerance policy" that says:
"The President’s executive order issued on June 20, 2018, directed, among other things, that the Secretary of Homeland Security maintain custody of alien families during any criminal improper entry or immigration proceedings involving their family members, to the extent possible. This order stated that the policy of the administration is to maintain family unity, including by detaining alien families together where appropriate."[1]
This is a return to how it used to be run - families were detained together.
This was not actually a policy. This was a side effect of a different policy. The policy was zero tolerance on criminal immigration law. That means, if an adult crosses the border illegally, they committed a crime and must be arrested for said crime. That part isn’t actually new, Trump just directed them to enforce the law. That’s where the issue comes in. When an adult male goes to jail, such as if I were to get a DUI with my kid in the car, I’m not allowed to take a kid in with me to jail. It doesn’t matter if they’ll be left alone with no one to care for them. No matter what, arrestees can not bring their kids to jail, ever.
So in this situation, the parent is arrested and charged with a crime, and the kids are held until a guardian can be located. And guess what? Many from Mexico or El Salvador actually don’t want to come up to the US and get their kids, if such a person even exists. The Obama admin built these “cages” for that reason. But, they didn’t enforce the law as much, so they were not used so often. They did build them and they did put kids in them though.