When Will Christians Become A Minority In The USA?

Many large, statistically valid surveys have documented the decline of Christianity in the United States. This is a long-term decline, not just a statistical blip. Since the trend away from Christianity is supported by large amounts of data, it is possible to estimate when less than half of the people in the United States will identify themselves as Christians. 

I plugged 70 years of survey data into a MS-Excel spreadsheet and used its linear regression function to forecast when less than 50% of the people living in the USA would identify themselves as Christians. I also did similar forecasts for "nones" (people with no religious affiliation). I did two forecasts, one using the whole 70 years of data, and another using only the most recent 20 years. This video discusses my calculations and graphs, together with some plausible explanations for the causes of these trends. 

The data that I used in this video is copyrighted by the Gallup organization and is used here in compliance with the “Fair Use” legal doctrine, because this video uses only my own graphs, which I have created, and summarize and extrapolate the data in ways that have not been presented by anyone else. 

The graphs and calculations are mine and have NOT been reviewed nor endorsed by Gallup or anyone else. 

Link to the Gallup data used in this video:
http://news.gallup.com/poll/1690/religion.aspx