MOSCOW – Michelle Obama brings her superstar glamor to Moscow this weekend as she accompanies her husband on his summit with the Russian president. But the American first lady, who has wowed publics in the U.S. and Europe with her easy elegance and charm, will perhaps face a bigger challenge in winning over a Russian public that has scant respect for women who grab the limelight from their powerful husbands. In a country where a presidential candidate once quipped he'd sooner pack his wife off to a convent than allow her to dabble in politics, Russia still has trouble with...