Leftwingers argue consistently that Americans don't pay very much in taxes by comparison with other countries. This argument has never held water, since it's irrelevant what other countries pay compared to us. My mother never bought the "everybody's doing it" argument and neither do I.
But apparently, some people think it's a real winner. Greg Mankiw has examined the data and come to different conclusions. He compares taxes as a percentage of a person's income (not GDP) and comes to some different results:
The United States is indeed a low-tax country as judged by taxes as a percentage of GDP, but as judged by taxes per person, the United States is in the middle of the pack.