Several YEARS ago?? Wow, justice moving with lightning speed there. How many anchor babies were popped out, how much in government bennies were sucked up during this time by those being investigated and ultimately removed?
Perhaps the investigators spent extra time to gather incriminating evidence on the higher ups? It might take time and wiretaps to capture incriminating statements that would prove knowledge of the conspiracy or participation in it.
As others are pointing out there won't be a significant deterrent effect unless the Americans who are benefiting face consequences for luring illegals into our country and protecting them while they are here.