The article reports that the 400 wealthiest Americans paid a lower tax rate than ever before, with some commentators noting that the effective tax rate for the wealthy has decreased significantly over the past 70 years. The article's findings are based on a graph showing tax rates on the wealthy dropping from 70% to 23%. However, the article's content is not available, and the discussion is based on the comments. The comments reveal a debate about the accuracy of the tax rates and the impact of exemptions, deductions, and credits on the effective tax rate.