 President Biden is being treated for mild COVID symptoms, according to his doc at home in Rehoboth Beach, Delaware. That's where ABC News senior White House correspondent Selena Wang is. Time is running out. Party leaders are planning to hold a virtual roll call to nominate President Biden in the first week of August. After he's nominated, he could still choose to step aside, but then the process gets more complicated. Some Democrats are arguing that replacing Biden late in the game could run into legal challenges.