FILE – In this Dec. 9, 2019, file photo, former first lady Michelle Obama listens to female students at the Can Giuoc high school in Long An province, Vietnam. Seeking to unite Democrats, Joe Biden has raced to line up supporters ranging from progressive icon Bernie Sanders to former President Barack Obama, whose administration sometimes irked liberals. But the person with the most influence may be Michelle Obama. (AP Photo/Hau Dinh, File)