I wrote this (partly) in the hope that people could quickly and easily get to grips with moral debates about immigration and also teach classes about them. I hope it will be of help to someone in this moment, esp the chaps on enforcement and undocumented migrants
https://www.routledge.com/The-Ethics-of-Migration-An-Introduction/Hosein/p/book/9781138659520?srsltid=AfmBOooLizMBfwNZpfq27QdQyLg88lX4GjJ2JTgzEBcvjrhSob9jKOPl