Ross Douthat’s 10 points about immigration is recommended reading for anyone sitting on the fence or who tends towards the open border position; even if you disagree, you’ll at least have an idea of what the opposition believe. Personally I agree with it all anyway and my opinions on the subject are as frozen in aspic as my musical tastes and haircut.
Not that many people are likely to change their minds, of course, this being a subject more of the heart than the head, on both sides of the debate. I’d go as far as to say it that immigration has become a sacred idea, and that many believe multiculturalism to be a moral good in itself, whatever the end result. This is why, uniquely among any subject discussed in the news, its downsides come with a caveat that ‘this subject will be used by right-wing extremists’. The outrageous behaviour of bankers, for example, is never reported alongside fears that the news will be ‘exploited by left-wing extremists’.