This is from the Pew Research Centre, via the Big Picture.
Europeans love this stuff: it is evidence Americans are ignorant idiots that don't know the first thing about politics and life in general ('Europeans' for my purposes includes large parts of the East and West coasts, such as San Francisco and New York).
I have always found these polls to be highly amusing, and barely relevant. First of all, a large number of voters are quite some way to the right or left of the political mainstream. These people already know that they will be voting Republican or Democrat: the name of the Defence Secretary is of no practical significance to them. Secondly, given the inability of most people to influence government, especially at the federal level, what is in fact remarkable is that so many people do know the name of the Speaker of the House.
In fact, the numbers are as high as they are because of politics' entertainment value, not any desire to influence the process of government - that would have been irrational.
And what about the main lessons to come out of this research?
More than a decade after the Internet went mainstream, the world's richest information source hasn't necessarily made its users any more informed. A new study from the Pew Research Center for the People & the Press shows that Americans, on average, are less able to correctly answer questions about current events than they were in 1989. Citizens who call the Internet their primary news source know slightly less than fans of TV and radio news.
Again, no surprise. Mainstream media are elitist - they are staffed by people who got good grades at school, enjoy opera and tend to find politics more interesting than Paris Hilton. The internet allows people more choice, and the intelligentsia can no longer dictate what people should be interested in. There is plenty of amusing stuff out there, and media oligopolies tended to supply way too much politics than a competitive market would. The internet is simply getting us closer to the competitive outcome - for better or worse.