The wives of our presidents walk in a minefield of expectations — the first lady is supposed to be the nation’s unroyal queen, its top hostess, a fashion plate at the same time as a child rearer, a career woman and an issue crusader, plus the eternal earth mother, strong yet nurturing, kind to all yet with a backbone that can bolster her man. No one can possibly live up to all those roles.

And on some level Americans understand that. They know that first ladies are not elected; their husbands are. So these real White House wives of Washington consistently are the most admired women in America, and most people are inclined to give them a break.

So it was last week when Post readers called and wrote to criticize a blog post and a column about first ladies.

The July 11 Post Politics blog entry on Michelle Obama’s 1,700-calorie excursion to Shake Shack in Dupont Circle for a burger, fries, chocolate shake and a Diet Coke elicited howls. Readers saw it as a trivial, News-of-the-World type story and a lowering of The Post’s standards.