Can Michelle Obama put America’s children on a diet?

WASHINGTON — If there’s any doubt that opposing childhood obesity is a political winner, as well as a noble cause, Michelle Obama’s upcoming trip to Mississippi, the nation’s most obese state, may be more proof.

Gov. Haley Barbour, a portly Republican who’s mulling a challenge to President Barack Obama in 2012, will join the first lady at a Wednesday event in Jackson promoting school nutrition and exercise. Barbour, a former lobbyist who heads the Republican Governors Association, recently said that if he lost 40 pounds, it would mean he’s running for president or has cancer.

Before heading south, Obama will speak Monday in Washington to the School Nutrition Association’s Legislative Action Conference. These appearances follow others that have gotten attention in recent weeks.