Most of us know or learn at some point the fact that many of the rich pay a lower percentage of their income in taxes than a middle income family. Example: someone like Buffet paying only 16% or 17% (while some of the very and ultra rich pay even far lower effective rates than that!), while his secretary, making vastly less income than Buffet pays a much higher rate than Buffet, such as 20%, or more. (Even though the income tax rates make it
seem to most people as if the reverse would be the norm.)
The reality:
Rich: many pay shockingly lower rates, especially the very rich.
Average people: Pay higher rates.
Fact checking the claim:
Clinton: Buffett said he pays lower tax rate than secretary
(or instead of a fact check, one could read an economics article discussing this in depth, if they think it's rare, and find out the reality)
We've heard the rationalizations for the special lower rates (I mean I read sympathetically the economic rationalizations/arguments in favor of those, not just some content free opinion pieces). But see, a lot of us don't buy those rationalizations, nor the even worse special breaks some get. We that have learned about some of that can make a reasonable guess at why Trump doesn't want his tax information released. He needs to maintain secrecy about that, one can guesstimate, as his voters might not like the bottom line at all.