It may seem a bit crazy to pour huge amounts of cash into lobbying efforts. But if you can spend a few hundred thousand dollars and make a billion, it’s probably worth the risk. As one savvy investor is well aware, it’s unusual to make that sort of return on investment by building factories and making things.

As The New York Times reported recently, hedge fund manager William Ackman stands to earn a billion dollars if he can run down the stock price of the supplement company Herbalife. And he’s trying to use the power of the federal government and state governments to do just that.

Ackman has pulled out all the stops. He convinced a member of Congress to send a letter to the Federal Trade Commission demanding an investigation. He paid for protesters to travel to Washington for a rally. He contributed $10,000 to the League of United Latin American Citizens, which then came out against Herbalife (the executive director eventually gave that money back). He lobbied federal and state regulators, including the Securities Exchange Commission and the Federal Trade Commission, to investigate.

He claims Herbalife is a pyramid scheme. But he doesn’t need to prove that it is. He just needs to use the power of government oversight to raise doubts about the company. “Could we get the world to focus on a company, could it get enough of a spotlight so that the S.E.C., the F.T.C., the 50 attorney generals around the country, the equivalent regulators in 87 countries, if any one of them, or at least any powerful member of that group, could we get them interested?” Ackman explained at an investor conference.

The efforts paid off in January, when Sen. Ed Markey (D-Mass.) penned letters to regulators after meeting with Ackman. “I have serious questions about the business practices of Herbalife and their impact on my constituents, and I look forward to receiving responses to my inquiries,” Markey wrote. Herbalife stock plunged 14 percent that day.

The stock has since recovered, but Ackman vows to maintain his crusade. And however this case plays out, it’s already made plenty of money for plenty of lobbyists. While fighting for its corporate life, Herbalife has joined Ackman in hiring D.C. insiders to exert inside-the-beltway influence.

Other companies have faced similar campaigns recently. Chevron just prevailed in a case that lined the pockets of plenty of Washington insiders. The New York Post says Kerry Kennedy, the politically-connected ex-wife of New York Gov. Andrew Cuomo, would have pocketed $40 million had that case gone differently.

No doubt other cases will follow. There’s no better place to invest than Washington, D.C., where the power of the federal government means relatively small campaign contributions and lobbying fees can be parlayed into hundreds of millions, even a billion dollars.