Does anyone really believe that any immigrants, legal or not, will be willing to tax themselves to pay for Social Security and Medicare for people who were too selfish to have enough children of their own? The United States started committing suicide in the 1960s after the baby boom. Filling the same territory with people who don't share the culture that formed the US in the first place means a new country, not a continuation of the historic USA.
You done said what has been happening. After my WWII service I was in the ‘build the USA’ crowd. Then I observed there came the Asians along with people from Mexico and Central America along with the Muslims and the Eastern European refugees. My opinion is that the large majority of these people had no interest or inclination to being true to the intent of the Founders and the Constitution. These people became a fertile ground into which Obama could plant the seed of ‘change’. Of course I also remember the famous ‘patriotic’(sarc) words of Bush I that the end of gulf war was the beginning of the ‘new world order’. This must have been Sharia music to the ears of the Saudis who hate everything about the USA except the need for oil. Obama was sure too recognize such with a deep bow before the Saudi King. We do have a new order of population and patriotism today in the USA. I am waiting to see how the 4th of July plays out.