Barack and Michelle Obama have endorsed Kamala Harris for president, saying in a spot released by her campaign early Friday that they “couldn’t be prouder” to help propel her to victory.The 55-second ad sees Harris taking a call from the Obamas while seemingly walking backstage at a campaign event. Former President Obama’s distinctive voice breaks in over the phone immediately: “Kamala!”After Michelle greets her as well, the video cuts to a title card—“The Obamas Call Kamala”—before shifting to