We’ve all heard about how actor-director Rob Reiner sponsored an initiative in California in 1998 to raise cigarette taxes to fund preschool programs. Reiner then became chairman of the state agency created by the initiative. And then he funneled $230 million of state spending through the ad and PR agencies that had worked on the initiative. And then he spent another $23 million of state money to support Proposition 82 this spring, to create universal preschool programs. He had to resign from his position, and voters turned down Prop 82.

But he’s not the only person sponsoring an initative that would benefit himself, his family, or his friends. A wealthy real estate developer who thought stem cell research would benefit his diabetic son spent $3 million of his own money to get Californians to create a $3 billion taxpayer-funded stem cell research organization, which he then became chairman of.

And now comes Vinod Khosla, a founder of Sun Microsystems and former partner in the fabulously successful Silicon Valley venture capital firm Kleiner, Perkins, Caufield and Byers, and recently number 1 on Forbes magazine’s Midas list of “the people who most successfully use venture capital to create wealth for their investors.” He’s been the subject of two admiring profiles in the Washington Post (one reprinted from Slate) in the past two days for his latest venture: ethanol. If Vinod Khosla says ethanol is a good investment, don’t bet against him. Or against fellow Silicon Valley megamillionaire Bill Gross, who says that “reinventing energy … dwarfs any business opportunity in history.”

But if it’s such a good investment, why is Khosla “supporting an initiative on this fall’s ballot in California that would tax oil companies to generate $4 billion to help encourage the use of alternative energy,” as Slate writer Daniel Gross notes? Khosla told Post columnist Sebastian Mallaby that he wants just a little help from the federal government, too: “Khosla wants government to require auto companies to make more flex-fuel cars that run on gasoline or ethanol.… Khosla wants government to require big gasoline distributors to install ethanol pumps at a tenth of their gas stations.” Oh, and a better subsidy.

Taxing your competitors to subsidize your industry is a rent-seeker’s dream. Usually you have to be more subtle about it. But if you have a “green” business idea, you can get liberal journalists to write gushing stories about you without even stopping to ask, “Hey, aren’t you going to benefit from these initiatives and laws you’re pushing? Isn’t that sort of like, you know, corporate welfare? Like we’re always accusing the oil industry of?”

We shouldn’t bet against Khosla. But if his latest investment is really such a great business opportunity, we should feel free to vote against subsidizing it.