You can be English without being Anglo Saxon.
Or are they descended from the British Romans? Or the Celts? Or Norse raiders? Normans? Or, and here's a crazy idea, are the lines so blurry and so unimportant that it doesn't really mean anything? Are things like "English" and "Swede" and "American" more a collection of loose adaptable ideas than a concrete exclusionary definition? Aren't national identities really just tools of the powerful during times of struggle with other powerful people desperate to inspire a sense among the common worker that they, too, somehow, have skin in the game?
Could it be that all of this just a bunch of bullshit? Norwegians immigrate into Sweden all the time and never once experience a person saying "yeah, but you'll never be SWEDISH Swedish, you know?" And of all the comments on this page, not one is addressing the obvious: you don't actually give two shits about splitting hairs on ethnic lines - it's all about the color of his skin.