This chart from Pew is interesting:
Click on the image to see the whole report.
For what it's worth, I don't think citizenship should automatically be granted to anyone who is allowed into the US, and I'm not so sure it should be automatically granted to everyone already living here, or everyone born here. I think there needs to be a discussion about what citizenship means, what it should mean, and how it should be earned. My concern with immigration and this blog is with individual rights; people's right to live where they please, trade with whom they please, and employ or work for whom they please.