Mitt Romney says he pays about 15 percent in federal taxes. Received opinion suggests we all ought to be just horrified by this. After all, even billionaire investor Warren Buffett professes to be dismayed that because (like Romney) he makes a lot of money in the stock market, and the tax rate on capital gains is lower than the tax rate on ordinary income, he pays a smaller slice of his income in taxes than employees who make much less. Romney, on the other hand, doesn't want to raise the capital-gains tax rate. Left-wingers think this is laughable on its face, writes A. Barton Hinkle. But the realities of inflation and double taxation prove Romney right.