Should we be outraged at how little Mitt Romney (like Warren Buffet) pays in taxes?

The Wall Street Journal notes that Romney (like Warren Buffet) makes his money from investments, so the income he receives has already been taxed "at the corporate tax rate of 35%." The 15% tax he pays sounds unfairly low, compared to the tax rate on wages and salaries, but it's not low at all if you see it as a second tax.

All income from businesses is eventually passed through to the owners, so to ignore business taxes creates a statistical illusion that makes it appear that the rich pay less than they really do. By this logic, if the corporate tax rate were raised to, say, 60% from today's 35% and the dividend and capital gains tax were cut to zero, it would appear that business owners were getting away with paying no federal tax at all.

This all-too-conveniently confuses the incidence of a tax with the burden of a tax. The marginal tax rate on every additional dollar of capital gains and dividend income from corporate profits can reach as high as 44.75% at the federal level (assuming a company pays the 35% top corporate rate), not 15%....

[T]he average effective tax rate on the richest 1% is already twice as high as that of the middle class.

But Romney needs to be able to explain this persuasively to the American people. He needs to be able to explain this while his opponents are gleefully screeching "15%!" It's a good test of his ability to be persuasive, as a good candidate must be. So step up and take the test, Mitt!