You're trying to, to unfortunately use an overused expression, have your cake and eat it too. You can't argue on one hand, that it brings in little revenue so it's insignificant, and second, that it massively alters behavior so it's super-significant. Remember, the tax only affects about 100,000 households; it doesn't even affect the capital gains tax for 99% of the country. But if it did, so what? The capital gains tax rates of the Clinton era hardly represented corporate soul-crushing socialism.
Actually, something can be insignificant and significant at the same time in that manner. We disagree there.
The more important number to look at in terms of behavior-altering effects is the percentage of capital gains in this country that is attributable to those 100,000 households, not the percentage of households affected in total.
And the Buffett rule does not affect what I believe is the most important issue in taxation of capital gains - short-term capital gains v. long-term capital gains.
