Nobody will say how much money Sen. Debbie Stabenow raised at a fundraiser sponsored by the organic-food industry on March 11—both the Michigan Democrat and her donors are keeping mum—but there’s no doubt about what she did just a few days later.

She came out against a pro-consumer bill that many farmers support but that her financial backers had urged her to oppose.

When reporters from The Hill asked about the curious timing, Stabenow’s staff brushed away their questions. In other words: Move along! Nothing to see here!

Yet there is something to see: The $35-billion organic-food industry’s emergence as a major force in Washington, where it seeks to buy influence among lawmakers who are willing to manipulate the power of government to achieve a priceless competitive advantage in America’s grocery stores.

Organic food is one of the great commercial success stories of recent years. As a lifelong rancher, I’ve watched its growth with admiration and awe. As a member of USDA advisory panels, I’ve tried to help develop standards and regulations that allow it to flourish. I respect the farmers who choose to participate in this sector of our agricultural economy as well as the consumers who prefer organic food, for whatever reason.

Let’s remember, however, that organic food has become a Big Business—and now it seeks to lobby lawmakers by bankrolling the likes of Stabenow, who is the ranking member on the Senate’s Committee on Agriculture.

From an office just a block from the Capitol, the Organic Trade Association has tried for years to require warning labels on food with genetically modified ingredients. Although its spin doctors have come up with compelling slogans about how consumers have a “right to know” what’s in their food, the group’s real agenda is to frighten people into thinking their food may contain ingredients that benefit from GMO technology and are unhealthy.

Even Senator Stabenow knows the truth. “Leading health organizations like the American Medical Association, the National Academy of Sciences, the FDA, [and] the World Health Organization all say that there’s no evidence that GMOs aren’t safe,” she has said, according to the Huffington Post.

This is why the “Nutrition Facts” that appear on food packages are silent on the question of GMOs. The science is clear: GMOs are safe to eat. Mandatory labels would confuse consumers, steering them away from safe products—and into the grasping arms of the organic-food industry, whose products are substantially more expensive than food produced on conventional farms.

Anybody who wants to avoid GMOs already enjoys an excellent option: Look for the USDA-approved organic label.

Vermont, however, may disrupt our satisfactory status quo. Under a state law that takes effect in July, food with GMO ingredients must carry a special label that will provide no useful information about health or nutrition but probably will entice grocery-store shoppers into buying costlier products.

A recent study says that if other states follow Vermont’s lead, writing their own rules and creating a patchwork of confusing and contradictory regulations, the costs of compliance will force the typical American family to fork over an additional $1,000 per year.

This invisible tax on eating is an assault on the interests of ordinary Americans.

To solve this problem, a bipartisan majority in the House last year passed the Safe and Accurate Food Labeling Act, which would keep labeling consistent across state lines.

Earlier this month, the Senate came close to approving its own version of the bill. Then Senator Stabenow attended the March 11 fundraiser, sponsored by the head of the Organic Trade Association and other industry executives.

“We need Senator Stabenow now more than ever,” said Gary Hirschberg, whose company makes organic yogurt. He cited his desire to stop efforts “to block mandatory GMO labeling.”

On March 15, just a few days after collecting campaign cash from Hirschberg and others, Senator Stabenow came out against compromise legislation on transparency and labeling.

She chose to take the side of a special-interest group over a common-sense solution to tell the truth about what farmers grow as well as to protect the pocketbooks of people who need affordable food.

Unfortunately, that’s how Washington works these days: Everything is for sale, including the principles of senators who ought to know better.