***In much of the US, and especially in the Midwest, actual Anglo-Saxon descent is very much in the minority (and does not even have a plurality for claimed ethnicities), with most white people being of other European backgrounds such as German, Irish, Scandinavian, Polish, and like***
Please, please, please understand that the term "Anglo Saxon" does not automatically mean the the people of England as such. They were not the original inhabitants of these islands since time immemorial. I'm sure you're aware of that!
Before the Romans occupied the island they called Britannia - from 54BC to 410AD - the Celtic tribes held sway here, and for many centuries prior to the moment Julius Caesar first set foot on the hallowed shores of Pegwell Bay, in what is now Kent, Iron Age tribes inhabited sites all over the undeveloped countryside of Britain of that time in history, and these people have left a multitude of relics in the form of hilltop forts, circular villages, long barrows, cromlechs and many other foms of evidence of their existence clearly visible today to all who wish to see them and who are interested in the so called Ancient Britons.
Some of these ancient hilltop fortresses of pre-history are still extrenely impreesive even to this day and still dominate the countryside of the present day - Danebury Hill, on the border between Hampshire and Wiltshire, is one such magnificent sight to see, both from the meadows below and from the very top, in the middle of the circular ramparts. Just below Danebury Hill is the site of former RAF Station called RAF Middle Wallop, would you believe - that being the name if a nearby village! RAF Middle Wallop was a fighter station during WW2, and the views from the hilltop fortress during the Battle of Britain in 1940 would have been truly awesome watching the German Luftwaffe planes zooming in low from the south east and letting loose their HE bombs on the RAF base below. The village of Middle Wallop is now a peaceful haven for commuters living in its beautiful surroundings but probably working in towns close by or even further afield.
Back to the Anglo Saxons - the Angles and the Saxons, and also the Jutes and the Danes, invaded Britain from the Continent, from what is now Germany, the Netherlands, Denmark, for the most part. THEY were the original Anglo Saxons, not the original people of what is now England. In time, however, they DID become the English, and were later joined by the Vikings, who swept in from the Northern parts of what is now Europe - Scandinavia in fact.
They all melded together in a nice, merry way and the foundations of modern day England were set, and in time the wonderful English Language began to take shape. The Angles gave England its name - and those parts of South Eastern England, between what is now the River Thames and The Wash (an inlet from the North Sea, between Norfolk and Lincolnshire, where King John unfortunately lost all his jewels in a sudden inrush of the tide in the 13th century) is called East Anglia to this very day.
East Anglia is an area of England with a very distinct and identifiable character, as well as a landscape all its own (think of John Constable, 1776-1837, the famous landscape painter) and furthermore - an accent all of its own - East Anglians themselves can distinguish the accents of Norfolk, Suffolk and Essex, the three counties of which East Anglia comprises, and they say they are all quite different from each other. However, Estuary is now becoming quite dominant in many areas, most definitely in South Essex, which borders onto the eastern fringes of Greater London.
East Anglia was the stomping ground of Queen Boadicea (or Boudicca if you prefer) - a very formidable woman, very fierce and warlike, who led the Celtic Iceni tribe against the Romans as they swept into the heartlands of her East Anglian territory. She snuffed it in 62AD.
So the term Anglo Saxon does not refer to the English exclusively. So all those modern day white inhabitants of the United States of America can indeed be called Anglos Saxon, even if their ancestors came from Northern European countries other than England (or the UK generally).
This is what they teach white Anglo Saxon British kids about THEIR forebears of many centuries past:
http://www.bbc.co.uk/schools/anglosaxons/invasion/index.shtml
Anglo Saxons as such will most certainly make up the majority of the UK population by a long way, and so it will continue in spite of immigration from outside of Europe, which the UK Government, under pressure from the Brtish public, is "determined" to control as a matter of urgency.
Conversely, an Anglo Saxon majority (or more exactly a white European majority) in the United States looks set to become an actual minority in the course of time, as I mentioned before.
Although it's none of our business (although in global terms it IS our biusiness in a way so long as the USA retains it's primary status in the Western world, the majority of Europeans, by a very wide margin, would be happy to see a black man take up the American Presidency.
If Great Britain (or Europe generally) was an American State it would probably be the bluest of all the blue American States that's for sure.