From that CBO link... > In this report, CBO analyzed the distribution of four types of federal taxes: individual income taxes, payroll (or social insurance) ta

From that CBO link... > In this report, CBO analyzed the distribution of four types of federal taxes: individual income taxes, payroll (or social insurance) taxes, corporate income taxes, and excise taxes. So it's not like it's including sales or property taxes or whatever else. For all intents and purposes, that's "income" tax. And the report is from 2013. This Washington Examiner article explicitly states (with a WSJ link for source) that the disparity has dramatically widened in recent years: > That may be the highest ever. Just two years ago, it was 84 percent, according to the Wall Street Journal. (https://www.wsj.com/articles/top-20-of-earners-pay-84-of-income-tax-1428674384 https://www.wsj.com/articles/top-20-of-earners-pay-84-of-inc...) Federal income tax provides nearly half of all federal revenue. It's not the only tax that matters, but it's certainly the most important and most visible. And any reforms will have the most impact to average citizens of any tax reform.