I'm not even American, and I know little of the details of the US Constitution, Declaration of Independence, US case law, and political systems, yet I got 20 correct out of the 33 (about 60%), so I'm astounded to read that US citizens on average did worse.
One thing I noticed on the results page though was "Average score for this quiz during November: 77.4%".
So, while I don't know what the average for US citizens in the figures for this month (and all time) was, it suggests that results reported in the story were most likely not a representative sample...
While that is the case for Gentoo, it is intended to be for hardcore Linux geeks. Apt or RPM based distros such as Redhat, Mandriva, or Ubuntu make it nice and easy to install - go to your package manager, search for "firefox", select "Firefox 3", and click "Install" (or "Apply") and when it's finished, the software has been installed.
That's nicer and more consistent (only one place to look) compared to finding and installing some Windows software. I'm not going to try to pretend that everything is easier using Linux, but it is a lot more user friendly than it used to be, and some Distros are concentrating very much on ensuring that they are as user-friendly and "plug and play"-esq as possible...
"The four building blocks of the universe are fire, water, gravel and vinyl." -- Dave Barry