In what passes for good news on Capitol Hill, a bitterly divided Congress finally took a step toward undoing the dysfunctional marriage of convenience between food stamps and farm subsidies. House Republicans this month pushed through a farm bill, minus nutrition for the poor. It was the first time since 1973 that a farm bill had advanced without food stamps — a program the Republicans say they’ll fund in a separate bill.

We take it as a positive sign. Farm subsidies and food stamps should be judged on their respective merits. Both need reform. Both should be cut back, farm subsidies more so than food stamps. It won’t happen if urban lawmakers feel compelled to support rural giveaways in exchange for farm-state votes to support feeding programs.

Most of this debate has focused on food stamps. Despite the “farm bill” moniker, the Supplemental Nutrition Assistance Program makes up 80 percent of spending in the existing farm bill that’s about to expire. Conservatives have recoiled at the program’s expansion over the past decade to 47 million Americans. The conservatives want deep cuts.

Democrats accused their Republican counterparts of being cruel to the needy. Even in a Washington environment of near-constant acrimony, the debate turned especially mean. Liberals suggested that reining in a fast-growing federal food stamp program was tantamount to starving America’s children.

That’s not true. In fact, the House Republicans’ gambit may be the best thing to happen for food stamps. The assumption that food stamps need farm-state votes to survive congressional scrutiny is based on past experience rather than a clear view of the future:

Food stamps do a lot of good. Fraud and abuse exist, but they’re limited. The program has grown too far too fast as a result of easier standards for qualifying. Still, the argument for continuing it is strong, and it can be funded at a level that protects the most vulnerable Americans while also taking essential steps to reduce federal spending. There is no reason to believe that Congress will hurt those truly in need.

Farm subsidies, conversely, are a relic of the past. They hark back to Soviet-style central planning. They funnel taxpayer money to a wealthy special-interest that hasn’t needed it in decades. Most ag subsidies should be eliminated, or at least drastically curtailed.

It can’t help food stamps in the long run to be joined with obsolete farm programs that make no economic sense. The political calculus is changing as more members of Congress understand that point:

Congress isn’t ready to do away with farm programs yet. We’re disappointed to see the House approve its food-stamp-free farm bill without scaling back the subsidies to big agriculture.

What’s more, this Republican bill is loaded with pork that flies in the face of the party’s free-market, small-government principles. It includes, for instance, a continuation of a so-called counter-cyclical program that pays farmers when crop prices fall below certain levels.

Worst of all, it includes a costly expansion of the misnamed “crop insurance” program: Farmers can use it to guarantee the revenue from their businesses, essentially locking in profits at taxpayer expense. The House bill would expand that boondoggle even more than the Senate has proposed in its version of the next farm bill —which, as in the past, marries food stamps to farm subsidies.

The House and Senate bills are so different that reconciling them won’t be easy. One (bad) option is a short-term extension of existing law. We hope the Senate will accept the House’s notion of keeping food stamps out of the subsidies debate. That would improve the odds of Congress someday ending the subsidy programs.

The still-powerful farm lobby sees that ultimate threat to its vested interests. Earlier this month, more than 500 farm organizations called on lawmakers to keep farm subsidies and food stamps together as one. That 500 ag-lobby organizations even exist is revealing by itself.

Time to bust up this unhealthy policy alliance. Stop allowing farmers to hold the most needy Americans politically hostage. Divorcing these programs is the best way to discourage a privileged slice of the population from exploiting the public purse.