Did you know that the federal government spends more money on welfare than it does on Social Security, or Medicare, or the military? Me neither, perhaps because it isn’t true. It’s the kind of hooey that the crankier, less-informed sort of conservative is all too ready to believe. Yet the highest-ranking Republican on the Senate budget committee has lately been spreading this meme, and a variation is included in Representative Paul Ryan’s proposed budget. It’s part of a larger bait-and-switch that Republicans have been playing against Democrats, making it harder for both parties to agree on necessary spending cuts that don’t harm those in need.

The budget committee poobah is Senator Jeff Sessions. In October, Sessions put out a press release under the headline “Welfare Spending the Largest Item in the Federal Budget,” a claim repeated uncritically by Eric Bolling on “The Five,” a Fox News chat show, and on sites such as National Review and Human Events. An urban myth was born.

“Welfare” is commonly understood to refer to Temporary Assistance For Needy Families (TANF), the block grant program that replaced Aid To Families With Dependent Children under the 1996 welfare-reform law. The federal government spends about $18 billion per year on TANF. Sometimes “welfare” is also understood to mean food stamps. The federal government spends $78 billion per year on food stamps. Combined cost: $96 billion. Annual expenditures on Social Security ($731 billion), Medicare ($486 billion), and defense ($718 billion) are each greater by a factor of five or more. (Throughout this column I’m using data for fiscal year 2011, the most recent available.)

Is Sessions a math dunce? No, he just subscribes to an unrecognizably maximalist definition of “welfare,” one that includes every single federal program that’s means-tested. He includes Medicaid and the Children’s Health Insurance Program, usually described as health care programs, which account for nearly half his total. He also includes Pell grants, job training programs, and various other functions that are “welfare” in roughly the same sense that all government spending is “socialism.” By stretching welfare’s meaning until it has almost none, Sessions is able to calculate the total welfare tab not at an underwhelming $96 billion, but at $746 billion, which is indeed more than the tab for Social Security, or Medicare, or defense. Then he adds in the state-funded part of these programs so he can say the total exceeds $1 trillion.

As recently as 2008, the federal tab was one-quarter lower. What happened? Sessions blames the Obama administration for encouraging too much participation, but the obvious problem is the economy. The Great Recession and weak recovery were a catastrophe for low-income people, making it necessary for the government to provide additional assistance, mainly through the 2009 stimulus.