Congressman Anthony G. Brown and former judge Katie Curran O’Malley both remember when they first met. It was the night before O’Malley’s husband, Martin O’Malley, then mayor of Baltimore and a gubernatorial candidate, announced that Brown would join his ticket as lieutenant governor. The O’Malleys invited the Browns over for a casual pre-announcement dinner. “She was a very gracious host, and it was a very pleasant evening,” Brown said. “He’s lovely, and his family’s lovely,” O’Malley recalled. But that was in 2005, and they are now on opposing teams, heading into the final stretch of a tight primary battle seeking the Democratic nomination to be Maryland’s next attorney general.