Immigration enforcement is the number one priority of this administration — beyond everything else. And when the DOJ makes that its number one priority, it means that they have to drop a bunch of other cases, including ones with far more serious consequences.
It is certainly possible that he simply doesn't understand this, so he is going to declare victory and then only realize that this fixes nothing for him.
But this war, unlike all his other problems, does not benefit from the median voter's lack of object permanence.