The Obama campaign came out swinging Wednesday in response to this shot across the bow from the Koch brothers posted on their website last Friday, which read in part:

Contrary to your assertion that we have “committed $200 million to try to destroy President Obama,” we have stated publicly and repeatedly since last November that we have never made any such claim or pledge. It is hard to imagine that the campaign is unaware of our publicly stated position on that point. Similarly, Americans for Prosperity is not simply “funded by the Koch brothers,” as you state — rather it has tens of thousands of members and contributors from across the country and from all walks of life. Further, our opposition to this President’s policies is not based on partisan politics but on principles. Charles Koch and David Koch have been outspoken advocates of the free-market for over 50 years and they have consistently opposed policies that frustrate or subvert free markets, regardless of whether a Democrat or a Republican was President.

Sure. Tell me another one. Jim Messina responded with equal and appropriate force:

But it is a cynical stretch to describe the political activities of your employers as furthering democracy when they are courting huge checks from special interest donors to pay for negative ads, with no public disclosure of the identity of those donors.

You argue that Americans for Prosperity is a grassroots organization of everyday citizens. But its emphasis on rolling back environmental protections and blocking a clean energy economy appears to be nothing more than an effort to promote the corporate interests of your employers and others who lavishly, and secretly, fund its operations.

Moreover, the negative ads AFP has run have been challenged as false by independent fact checkers.

The Los Angeles Times has reported that in 2010, Koch Industries and its employees marshaled hundreds of thousands of dollars behind the election of their Republican allies on the House Energy and Commerce Committee, who have pursued their interests in Congress. In fact, nine of the 12 new Republicans on the committee signed AFP’s pledge to oppose President Obama’s proposal to regulate greenhouse gases.

And now it’s been reported that your employers and those close to them intend to spend $200 million in an attempt to defeat the President. You note in your letter that Americans for Prosperity has tens of thousands of members and contributors from all walks of life across the country, suggesting that this is the source of AFP’s funding. There is one way to verify your point: disclose those donors for the public to make that judgment.

What is known about the Kochs’ agenda and business practices would give most Americans pause. According to the Kansas City Star, Koch Industries has enriched itself by keeping oil off the market, storing it in offshore tankers and waiting to cash in when the cost of oil rises. The Koch brothers have also been vocal critics of the administration’s investments in clean energy alternatives. Our energy strategy cannot be set by what’s best for the pocketbooks of politically-connected oil and gas executives. It must be driven by what’s best for the American people, our economy, and our energy security.