The fight over the farm bill dragged on longer than anyone in Washington expected. Legislation that had been pretty easy to push through in 2011 became a kidney stone in 2013—Republicans wanted to use the legislation to cut into the food stamp program, adding more work requirements and reducing costs by $40 billion over 10 years. Democrats balked; the bill went down. Republicans split the farm bill from the food stamps funding. Democrats didn't move any of that through the Senate.
So, at last, we have a compromise. The farm bill will cut food stamps by $8 billion over 10 years. That's a 1 percent annual cut, down from a 5 percent cut. It includes a popular gimmick to bar food stamps for lottery winners—sorry, you dozens of people who become instant Fox News celebrities!
What broke the impasse? The best clues I've seen come from this Molly Ball piece about the rage of the farmers lobby, which had already started punishing Republicans who voted against farm subsidies. Republican pressure to stick to the deeper cuts came from outside the House and Senate ag committees, which are still run by members from rural districts. (That's generally who wants on those committees.) This just wasn't the issue for the GOP to run on in a year when it needs to take Senate seats in Arkansas, South Dakota, Louisiana, and North Carolina.