In one appearance, Michelle Obama did for Balenciaga boots what it took a hit TV show for Sarah Jessica Parker to do for Manolo Blahniks. During the most recent stop on the book tour for her bestselling memoir Becoming, the former first lady dropped by Brooklyn’s Barclays Center Wednesday night for a discussion with Parker. While the Sex and the City star was clad in a holiday-appropriate sequin dress, Obama’s sparkly $3,900 Balenciaga boots got all the attention. In fact, by Thursday afternoon, the boots were trending on Twitter and were nearly sold out on the Balenciaga website. As a...