One cannot possibly evaluate any particular such issue without a thorough understanding of the many others that are connected. It's like trying to see what picture a puzzle makes when you only have a handful of pieces.

Why are people so concerned about immigration?

• Because those people will take off-the-books work and not "contribute" via taxes?

Yeah, well, taxation is theft.

• Because their presence makes it harder for you to get a job?

Tough luck, that's the free market; you don't have a right to a job.

• Because they will commit crime?

Some will and some won't, so it's immoral to address this issue with broad-stroke non-solutions that affect the innocent.

• Because they infiltrate your neighborhood with their culture and fuck up your comfortable little nest?

Too bad, that's life, things change. It's not immoral to move into a neighborhood en masse, and nobody owns the continent, so there's no right of defense against trespass at play.

• Because they take advantage of government programs like welfare?

Government is slavery; how about addressing that little tidbit and thus cutting off the root of the problem instead of worrying about how the leaves are blowing?

Principles - that's what's missing. The deliberate dumbing down is in full effect, and anyone up in arms about immigration needs to go back to Philosophy 101 and brush up on their Plato. We're so far from being mature rational adults it would be laughable if it weren't so tangibly perilous.