WASHINGTON — Often maligned, the potato is fighting back.

The spud has had a tough time lately. In the last year, it has been marginalized by new school lunch rules, demonized by a popular television program and blamed for the nation’s obesity epidemic. Health advocates and government officials have pushed to take them off lunch lines, where kids often reach for the crispy treats instead of greener vegetables.

Now some in Washington say they’re fed up with the war on fries. In a letter to Agriculture Secretary Tom Vilsack this month, 40 Republicans and Democrats in Congress questioned his department’s proposal to reduce the amount of potatoes and other starchy vegetables in school meals to about two servings a week, saying they can be a tasty, healthy way to provide potassium, fiber and other nutrients at a low cost.

According to the Wall Street Journal, Sen. Susan Collins, R-Maine, at a March Senate hearing on the USDA budget, hoisted a standard-fare brown-skinned spud in one hand and, in the other, a head of iceberg lettuce, which hasn’t come under explicit federal scrutiny. One medium white potato contains nearly twice the vitamin C “as this entire head,” she said, asking: “So my question, Mr. Secretary, is what does the department have against potatoes?”

It’s a refrain some in Congress are using more frequently to describe the Obama administration’s efforts to get kids to eat healthier foods — the government shouldn’t be telling kids what to eat. Should it be up to USDA to decide that potatoes can’t be eaten responsibly?

“I don’t think that’s what the federal government should be doing in general,” says Rep. Bill Owens, D-N.Y. He says he signed the letter after school lunchroom workers in his district came to him with concerns.

Since the guidelines apply to federally subsidized meals, schools are generally fine with broad federal guidelines on nutrition — how many servings a week children are allowed of grains or vegetables, for example. But many schools have balked at attempts to tell them exactly what foods they can’t serve.

“I feel that guidance is helpful, but that micromanagement is not,” says Doug Davis, food service director for Burlington, Vt., schools. “Having standards is important, but limiting foods by category is really challenging.”

Davis says he has worked hard over the past few years to source more foods locally and forgo processed foods. The potato grows well in his part of Vermont — so well that children in his school district are growing their own to eat off the lunch line. His lunchroom features all sorts of healthy potato dishes, including a baked potato bar.

“I don’t feel like potatoes or french fries are the enemy,” he said. “What we need to do is strike a balance in what our kids are eating.”

Health advocates say that is exactly why potatoes should be restricted. Because children eat so many potatoes already, schools should focus on providing more variety.

“Kids are not eating enough vegetables and when they do eat vegetables they are eating potatoes way too often,” says Margo Wootan, director of nutrition policy at the advocacy group Center for Science in the Public Interest, which pushed for the standards. “Too much of anything, even a good food, isn’t healthy because people need to eat a variety of foods.”