How Bad is the Ignorance Problem in the United States?

In short? Bad.

To give an overall flavor, here is a collection of data from a number of polls on American belief in evolution, correlated to a number of factors:

The Majority of Republicans Doubt the Theory of Evolution | Gallup, 2007
40%-50% of the public accepts a biblical creationist account of the origins of life | Pew, 2005
Only 26% of Americans believe in Natural Selection | Pew, 2005
In the year 2009, 200 years after Darwin’s birth, only 39% believe in the theory of evolution, and 36% have no opinion either way | Gallup, 2009
79% of those with a high school education or less either don’t believe in evolution or have no opinion either way | Gallup, 2009
27% of those with postgraduate degrees in the United States either don’t believe in evolution or don’t have an opinion either way | Gallup, 2009
Among those who seldom or never go to church, 45% either don’t believe in evolution or have no opinion either way | Gallup, 2009
Of those who go nearly weekly or monthly, 70% either don’t believe in evolution or have no opinion either way | Gallup, 2009
And finally, in the year 2009, in the United States of America, only 39% believe in evolution | Gallup, 2009

Here’s Gallup’s implications summary:

This makes me sad. ::