We have laws and Trump will collide with those if he becomes president. Paul Ryan is speaking of laws when he says, “I can’t imagine how it could happen.” Because Trump says it doesn’t mean it will happen. Every person he wants to deport will have to go to court to determine if the person is illegal. Trump doesn’t believe that but he is no judge and judges say that has to happen. Paul Ryan knows the laws and Trump does not or he is ignoring them (our present president ignores them, too.
There are probably a few hundred thousand ignored and unenforced deportations orders in existence now. And 40% of illegal aliens are visa overstays and those should require little or nothing in the way of hearings since they are clearly in violation of the terms of their visas.
If there were no punishment for bank robbery, I believe there would be many more bank robberies than there are.
Some of us don't rob banks because it would be an unethical or immoral thing to do. Many others don't do it because they fear being punished for doing so.
If you make using a false Social Security number a crime which carries a five year sentence, I don't think you will have to sentence many people before it stops happening. It's just not that difficult to detect and prove.
Once you stop illegal use of Social Security numbers, the next step is to punish employers who fail to properly check numbers.
At the same time, you start checking the public school rolls. If the child of an illegal can't obtain an education, it is not my fault or your fault, it is the fault of the illegal and should be treated as child abuse. Let's see the illegals set up their own private schools or take their children back to their home countries.
I think you are making this sound far too difficult. Like any important task, you identify the goal and the best ways to achieve it and then you take action. It can be done. It should be done. I hope it will be done.