Two prominent Republicans, New Jersey Gov. Chris Christie and likely 2012 presidential candidate Mike Huckabee, came to the defense of First Lady Michelle Obama’s efforts to reduce childhood obesity. Speaking on separate Sunday talk shows, the Republicans said they stood behind Mrs. Obama’s “Let’s Move” campaign despite conservative criticism. Mr. Huckabee, a former Arkansas governor who shed many pounds himself when in office, said on “Fox News Sunday” that obesity is a problem threatening the welfare of the entire country. “What Michelle Obama is proposing is not that the government tells you that you can’t eat dessert,” Mr. Huckabee said....