What type of documentation you think these people bring with them when they cross the border? do you really think they carry birth certificates and proper ID with them? If they didn't separate the kids and then one of these "parents" abused the kid while in US custody you would blame Trump for that.
And I'm not a "Trumpist", so you can go **** yourself with a tire iron if you continue with that crap.
Documentation isn't the only tool one can use to determine whether or not a family is a family. Border agents are trained to look for this. People like you, who support 100% separation of children from families, are not.
Sure, abuse can occur if you don't separate them. But guess what - it can and does occur when you do. Abuse from other kids, abuse from their guards, the overall abuse of being in a foreign country, away from your family, and no way of knowing what is going to happen, and for young kids - no understanding of why this trauma is occurring. Kids can indure a lot of trauma if they have their family to support them. People like you seem to think migrant children are expendable. You would never ever tolerate this being done to American kids.
Let's say, for example, the administration decided on a 100% policy towards drug offenses - no matter how minor, like even smoking a joint. Every child would be separated from the family and adults and children may or may not know where the other is. Children would be warehoused in large (for profit) incarceration centers. The government would decline them access to things like flu shots (usually recommended for crowded situations), communication with legal help would be curtailed, and there are not enough adults to adequately monitor safety, and some of those adults themselves would commit abuses. Food would be found to be substandard and sanitary supplies in short supply or lacking. Maybe it's YOUR kids.