As senators cast their votes today on the 1,139-page, $955 billion farm bill, the unseen backdrop is the more than $26 million in campaign cash that agribusiness has pumped into their political campaigns. All but two members of the current Senate have received money from these donors who represent every possible agriculture concern, from sugar growers to dairy farmers to chemical manufacturers and more.

It’s an axiom of agriculture politics that agribusiness interests concentrate their generosity on members of key committees who write and fund the farm bill. As the graphic below shows, the current Senate is no exception.

According to analysis of data downloaded from Influence Explorer, 42 percent of this agribusiness campaign cash flows to 15 senators, 13 of whom sit on either the Senate Committee on Agriculture, Nutrition and Forestry or the Agriculture Appropriations Subcommittee, or both. The other two have seats on the Senate Finance Committee, which writes tax law, as do several other top recipients of agribusiness contributions.

The top Senate recipients of agribusiness campaign cash between 2008 and 2012 largely hail from farm states, with senators from South Carolina, Kentucky, Michigan and Kansas topping the list. These are states where crop insurance subsidies, price supports, and commodity marketing programs make a big difference to constituents' pocket books.

But everybody in this country needs to eat, and the policy set by the farm bill, which is up for reauthorization every five years, has effects far beyond the farm belt. By far the biggest expense in the farm bill is the nation's food stamp program, which accounts for nearly 80 percent of the bill's price tag, or $760.5 billion. This reflects a cut of nearly $4 billion, but the Senate's proposed reducations are far less than the $20 billion in cuts over ten years proposed in the bill passed by the House Agriculture Committee.

The Senate bill also makes cuts in traditional direct payment programs for growers of various crops; however, much of this money is reallocated to one of the more controversial programs in this year's bill: crop insurance. Under this program, taxpayers subsidize the bulk of the cost of insurance plans taken out by farmers. Last year, when farmers in much of the nation were facing a drought, costs of the program increased to $16 billion. Critics argue that the program is poorly conceived, amounting to income insurance that ensures farmers will receive taxpayer-subsidized high profits in bad crop years -- more than they would have made if the crops were healthy.

Sen. Debbie Stabenow, D-Mich., who chairs the Senate Agriculture Committee, ranks third among top recipients of agribusiness campaign cash, is a strong champion of the crop insurance program, and has pushed to include more farmers among the ranks who qualify for the program, including Michigan cherry farmers. Stabenow has collected some $90,000 over the course of her Senate career from PACs and employees of companies and trade groups that are lobbying for expanded crop insurance.

Other recipients of ample agribusiness campaign cash have also pushed for programs for donors. Sen. Thad Cochran, R-Miss., who serves as the ranking member of the Senate Agriculture Committee and also holds a seat on the Agriculture Appropriations Subcommittee, was one of several southern senators pushing to make sure that there was a target price commodity program for peanut and rice growers. Last year southern senators voted against the farm bill because it didn't include this provision. Peanut growers appear among Cochran's top campaign donors over time, according to Influence Explorer. Cochran is also up for reelection in 2014, making the push for campaign contributions all the more important.

Ranking second in agribusiness contributions is Sen. Mitch McConnell, R.-Ky., who has three ways to help agribusiness: He served on both the Agriculture Committee and the agriculture appropriations subcommittee. Last but not least, he's the Senate Minority Leader. McConnell, also up for reelection next year, has long been a fierce advocate for the tobacco industry, most recently leading the successful opposition against an amendment that would have prohibited tobacco farmers from participating in the crop insurance program. McConnell ranks second for tobacco contributions overall in Congress since 1989, according to Influence Explorer.

The ultimate fate of the farm bill remains murky, though the Senate is expected to pass its version today. Last year, after the Senate approved a farm bill, it died in the House. But there is more pressure to act this year, as the current five-year program is set to expire in September.

The House is expected to take up its version of the farm legislation sometime next week, and debate is expected to be fractious. If the House manages to pass a bill, a House-Senate conference committee will have to hammer out differences between the two chamber's versions. The resulting bill would then go back to both chambers for a vote. Sunlight will continue to follow the legislation -- and the influence surrounding it.

(Graphic: Tin Nguyen/Sunlight Foundation)