When the food stamp program was first expanded nationally in the 1970s, just 1 in 50 Americans participated. Today, 1 in 7 Americans receive $134 each month, at a monthly cost of more than $6 billion. With the bipartisan Farm Bill going through Congress right now, these high levels of dependency may become permanent.

Some 70 percent of the nearly $1 trillion Farm Bill recently passed by the Senate will be spent on food stamps -- that's $770 billion over ten years. The food stamp program, renamed the Supplemental Nutrition Assistance Program, or SNAP, has grown exponentially in recent years. An estimated 45 million Americans received food stamps in 2011, at a cost of $78 billion. That's a twofold increase from just five years ago when 26 million people received benefits at a cost of $33 billion.

The weak economy has played a role in the increase of food stamp spending, but that's only part of the story. In fact, food stamp enrollment increased and spending doubled, even as unemployment and the poverty level dropped modestly between 2007 and 2011. The more important part of the story comes from the eligibility changes implemented by the Bush and Obama administrations.

The 2002 Farm Bill expanded eligibility to noncitizens, increased benefits for families with more children, adjusted benefits for inflation and made it easier to enroll. Further easing of eligibility requirements followed in the 2008 Farm Bill, which contained more than 30 provisions relating to food stamps, including higher minimum benefits. As the data show, spending after changes in eligibility grew by $185 billion between 2002 and 2008.

Similarly, the 2009 stimulus bill scrapped limits on SNAP benefits to adults without children and raised the maximum benefit by 13.6 percent through 2014. According to the Congressional Budget Office, about 20 percent of the $198 billion growth in between 2009 and 2011 can be attributed to the new eligibility standards, and hence will not go away once the economy recovers.

In theory, you cannot receive food stamps if your gross monthly income exceeds 130 percent of the poverty level. This means that a family of three qualifies if it makes roughly $2,008 a month, or $24,096 a year. Additionally, assets must fall below certain limits. For instance, a household with no elderly or disabled members is ineligible if one has a bank account or vehicle that is worth more than $2,000.

But these are federal government standards. States also have a certain level of flexibility with regard to eligibility. As Greg Beato of Reason magazine explains in a 2010 article, many states open them up to anyone receiving funds from the Temporary Assistance for Needy Families, or TANF, program. In practice, applicants with gross incomes well above 130 percent of the poverty line are now eligible.

Many states also abolished the asset tests for recipients. As a result, enrollees may include families with no income but tens of thousands of dollars in savings or homes. For instance, CNN Money's Adam Reiss and Poppy Harlow recently described how New Jersey's Morris County -- where the median income is $91,000 per year -- has seen food stamp enrollment rise by 240 percent since 2006.

This is unlikely to change as long as states are rewarded some $500 million by the federal government for boosting enrollment, and as long as nearly 10 percent of food stamp costs go to program administration. More important, despite the quadrupling of food stamp spending, several Republicans voted with Democrats to defeat reforms sponsored by Sens. Rand Paul, R-Ky., and Jeff Sessions, R-Ala. The political will to rein in this program just isn't there.