20 years ago, when I was still a prosecutor whose duties included handling immigration cases, I took an afternoon off and went to Duke Divinity School's library to pore through recent and archived issues of America Magazine, hoping to get a better grip on the Church's stance on illegal immigration.  I have a love-hate thing with the Jesuits, but I usually look to them first for advice on moral matters.  (Yes, Neko, I did go to Jesuit.)  This time their advice was unusually important --- I'm Catholic first, American second.  No real luck finding the right article.  

20 years later comes this great piece in America Magazine titled: "I am Catholic—and I don't know what I'm supposed to believe about immigration,"  America Magazine.  See: https://www.americamagazine.org/politics-society/2017/09/12/i-am-catholic-and-i-dont-know-what-im-supposed-believe-about  

It still doesn't answer the questions, but it does pose the right ones, and that's a step closer to the truth.