This is my last OT post. No responses will come for anything written about it!
Immigration is absolutely a net good, period full stop. It's pretty much win win win all the way to the bank. Low skill, high skill, no skill doesn't matter. That said, if the welcoming society isn't, well, welcoming, it ends up in the situation France and Germany are in -- tons of jobless, poorly educated and irate immigrants. America might not be coping perfectly, but it's doing a heck of a better job than most of the other major players -- immigrants who somehow manage to make it into this barb wired country have a reasonably good chance of success, where success is defined as a higher standard of living than the one they left behind. That said, America does have the ass backwards policy of subsidizing foreign graduate/doctoral degrees and then, upon completion of their studies, rejecting the requests of that same group for green cards. I mean, hello, we just paid to educate those people and they want to live here, let them!
Population growth is a net good so long as it doesn't affect the dependency ratio. Once things start getting lopsided, problems emerge. The solution is most certainly not have more kids -- thanks to the lead time on child production, you'll just end up making the problem significantly worse in the short term, and repeating it in the long term.
Immigration is so gosh darned awesome and a special case because immigrants are usually people who A. had the balls/ovies to swap countries, no mean feat, B. are committed to working hard to better themselves (see A), and C. overwhelmingly adults. It's like people are popping into existence de novo! No paying for schooling, natal care, any of that. Fully formed (sans the language barrier, four to eight years of Spanish education really ought to be required of the average American, it would improve our country soo very much) productive citizens literally from day one.
My history major comment was intended as a zing. If anyone was offended, well, sucks to be you I guess? Feel free to take a pot shot at me! I recommend mocking my hair, it is quite mediocre.