Only if you take into account the marginal rates and ignore the many, many breaks and loopholes.

OK, what about the many "breaks and loopholes." for the other tax brackets? I'm in the 25% bracket (Married filing jointly, $68,001 - $137,300) and I paid under 6% effective rate for each of the last few years.

Buffet is not talking about income tax. He's talking about capital gains taxes, since most wealthy people are making money from investments, not paychecks.