WASHINGTON — First Lady Michelle Obama is staging picture-perfect photo ops on her tour of China — but back home, her East Wing office is fraught with tension and anxiety, according to a new insider account. Her office “can be a confining, frustrating, even miserable place to work,” writes former White House press assistant Reid Cherlin in an article in The New Republic. “Jealousy and discontentment have festered, as courtiers squabble over the allocation of responsibility and access to Mrs. Obama, both of which can be aggravatingly scarce,” he continues. Michelle Obama has a strong approval rating (69 percent in...