First Lady Michelle Obama sits with students during a visit to the LAMB bilingual school.White House flickr streamHer husband got dealt a difficult set of cards in taking over the post-Bush II presidency–and has arguably played them quite badly. He now finds himself in a tight political corner: caught between an emboldened Right, an angry Left, and a shrivelled middle.

But Michelle Obama abides, as fabulous and beloved by the electorate as ever. She has built up a tidy store of political capital. She plans to spend it “by spearheading an initiative to reduce childhood obesity that, she hopes, will create a legacy by which she can be remembered,” reports Sheryl Gay Stolberg in The New York Times.

Reducing childhood obesity is a goal that few could argue with. But really it’s an appealing way to frame a massive problem with powerful vested interests behind it: a food system that churns out low-quality, environmentally ruinous food and robust profits for a few companies.

If the First Lady plans to confront the issue in a serious way, she’ll soon be knocking heads with those very companies. She has already gotten a taste of the coming pushback, just by planting an organic garden.

It will take every iota of Ms. Obama’s considerable grace, smarts, and popular appeal to “move the ball” (as she puts it) on the diet-related maladies that confront the nation’s children. The sustainable food movement has never had a more appealing or high-profile champion.