I'm the moderator who deleted it. Yes, it did have the correct facts to answer, and I admit to wrestling between editing it and deleting. The downvotes were obviously coming in, and I'm surprised it wasn't flagged. The problem I had with editing it was really a problem that the answer itself introduced, that of being a political/cultural attack. I could have easily edited it (and maybe that was better thing to do - I don't know for sure), but then isn't that then just implicitly applying my own political/cultural opinion by erasing yours out? That didn't feel right either. I eventually decided that deleting was the option I would go with. My thinking was that this could be handled like a question close. If the political/cultural attack is removed, I'm quite happy to undelete it.
So why did I moderate this at all? Well we moderators are human and we bring our baggage with us just like anybody else. I've been highly active on an immigration site that tacitly allowed political and cultural attacks on nationalities. And nobody was safe. Things got nasty, and it drove me and many other long term contributors away. Moderation finally caught up and put the hammer down on it hard. Really hard. But that damage that was done has never really been undone. I just don't want to see that happen to this site. I know that at times there is a thin line between valid criticism and pointless off-topic attacks. This is not a new thing here. Immigration policies and their enforcement are easily intertwined with the politics and deeply rooted culture of any nation. It can be hard to be objective even for those of us who strive the hardest to be so, and usually are very successful at it.
In my opinion, and from my previous bitter experiences, this post crossed that line. If you wish to opine your grievances (which may indeed be justified) about the politics and culture of current American policy with regards to illegal immigration, we can head on over to Politics.se and have at it. This forum is not for that sort of discussion, and as a moderator, I'd like to keep it that way as much as we reasonably can.
(I should note, that even at Politics.se, there's a good chance that your post gets the same treatment over there, likely flagged very quickly. The mods very obviously have their own agendas and politics. Just like us here, they're human. But they do make a rather strenuous effort to also keep this kind of stuff off their site - even stuff they so very clearly agree with -, and with good reason).
Here's a snapshot of the answer in dispute for those who can't see it: