In December 2006 the Wall Street Journal published an article on President Bush's approval rating. It found, for example, that just 19% of Americans described themselves as more confident that the war in Iraq will end successfully. News articles tend to be brief in describing sample surveys. Here is part of the Wall Street Journal's description of this poll:
"The Wall Street Journal/NBC News poll was based on nationwide telephone interviews of 1,006 American adults, conducted December 8-11 by the polling organizations of Peter Hart and Bill McInturff. The sample was drawn in the following manner. 520 geographic points were randomly selected proportionate to the population of each region and, within each region, by size of place. Individuals were selected by a method that gave all telephone numbers, listed and unlisted, an equal chance of being included." It appears that the sample was taken in several stages. The first stage no doubt used a stratified sample, though the Journal does not say this. Explain why it would be a bad practice to use an SRS from a large number of "geographic points" across the country rather than a stratified sample of such points.