Since he called for higher taxes for the wealthy, Republicans have called for Warren Buffet to release his tax return. Except he already did. (More)

Last month, billionaire investor Warren Buffet wrote an op-ed for the New York Times calling on Congress to stop coddling the super-rich. Earlier this week, President Obama spoke in the Rose Garden on taxes, and proposed what has been dubbed the “Buffet Rule” – that no millionaire or billionaire should pay a lower net tax rate than working class Americans. Democratic leaders and many other progressives have praised the proposal. Not surprisingly, Republicans haven’t.

In fact, several have called for Buffet to release his tax return to the public:

Sen. John Cornyn (R-TX): If he’s going to be the gold standard, so to speak, in terms of what our tax policy should be, let’s look at them. I know that Mr. Buffett’s not likely to release his tax records but I’ll bet what it’ll show you is that most of what he earns is from capital gains, which is taxed at a 15 percent tax rate rather than deriving it as income [for] which he’d pay a much higher tax rate. If he doesn’t derive ordinary income and if all of his, what he puts in his pocket is based on capital gains, I think that would be an important information.

Sen. Jim DeMint (R-SC): I’d love to see Buffett’s tax returns so we can see what he’s really doing, because he’s kind of operating in the dark here, making some claims. If he’s paying taxes on capital gains, taxes have been paid by the corporations before they gave it to him. He may not be paying it personally, but the tax is being paid at a higher rate than his secretary’s making.

Rep. Tim Huelskamp (R-KS): Given the use of your name and your story as the guiding force for the President’s policy prescription, it is my hope that the evidence to justify such a change in policy will soon be available for public review.

Okay. But Buffet already made his tax return public, a month ago on The Charlie Rose Show:

Buffet: Well, I think – what really gives the low rates to the very rich like me is the – is the low tax on dividends and capital gains. If you take these rich people what the IRS singles out, from 1992, they’ve almost had a tenfold increase in capital gains. They’ve had a tenfold increase almost in dividends. And those – those are taxed at 15 percent and there’s no payroll tax on it. Now, the payroll tax accounts for almost as much revenue to the government as the income tax. It’s close – $800 billion plus on payroll taxes last year; about $900 billion on income taxes. That’s where the money comes from in Washington. And they don’t get any payroll tax to speak of on my income. I’ve got my tax return here.

Of course, that was probably just Buffet’s “short form” 1040EZ. Should Americans demand to see his “long form” 1040, including all schedules and supporting documents, signed by Buffet, his wife, and his (probably Kenyan) accountant?