I am so far batting .750 with my conservative friends trying to convince them that mass deportation is an issue they should be concerned with. Every one of them begins by pointing out that "illegal immigration is illegal, full stop". Here are the issues they're not immediately considering:
* For many Latino immigrants, the wait list for permanent residency is over 20 years long. The wait isn't that long because we want to restrict immigration; we broadly agree that if we drastically reduced the immigrant population in the US, the economy would suffer, because those people are staffing the meat packing plants, cleaning the hotels, working the line at practically every high-end restaurant, harvesting crops, laying bricks, and putting up tile. Rather: the 20 year wait list is simple bureaucratic cruelty: there are loud constituencies who are uneasy about formally allowing people to stay here while being totally content with allowing them to work here undocumented, so long as they're kept second-class.
* That's bad enough, but not dispositive. The real problem is that we've created the expectation that people can work here for years and years without obtaining permanent residency, and so people put down roots and then have children here. Children born in America are American citizens, full stop. We are idiosyncratic in having a Constitution that guarantees birthright citizenship, but we do, and we are a nation of laws. To deport undocumented workers with children born here is to put young American citizens in the position of having to choose between losing their parents or their home country. Pointlessly. We owe our fellow citizens better.
* A huge number (pretty much everyone agrees it's a plurality) of undocumented workers are undocumented not because they've done something wrong, but because they've somehow fallen off their visa track --- which the law makes incredibly easy to do! We put them on an untenable 20 year legal obstacle course that really requires professional representation to complete. They spend that time working and raising children. Then we punish their children for technicalities, while quietly replacing them with other Latino immigrants.
* The due process concerns about deportation are overwhelming. More than 70% of deportation cases in which the subject is represented by an immigration attorney fail --- the immigrant isn't deported. But the overwhelming majority of deportees aren't represented, because we don't guarantee counsel to people in immigration court. All we give them is a translator. If I sued you on some bogus libel charge for pissing me off on HN, how well do you think you'd do if you were denied a lawyer?
I am ultimately ambivalent about immigration enforcement. I recognize that we are in many ways more lenient than much of Europe. My objection to the big dumb wall isn't moral, it's just that it's a big dumb waste of money.
I am not ambivalent about pointlessly tearing up, or, worse, forcibly relocating families that include American citizens. There are hundreds of thousands of those. I would absolutely quit a job, refuse investment from a firm that supported, or sever ties with a client that participated in a mass deportation program that forced children to choose between their parents and their country.