 ABC News, I'm Michelle Franzen. Day two of the Republican National Convention getting underway in Milwaukee. Unity is the theme tonight. Speakers include one-time rivals of Donald Trump, Nikki Haley and Ron DeSantis. Security is heightened following the assassination attempt of the former president in Pennsylvania. And investigators are looking into the gunman's background and reviewing security. Butler County Sheriff Michael Sloop, meantime, is defending his deputies.