WASHINGTON — Six years ago, as the “money, money, money, money” chorus of his reality TV show’s theme song blasted, Donald Trump stepped out before the nation’s largest gathering of conservative activists for the first time. The crowd was less than adoring, occasionally laughing at and booing the longtime former Democrat. But Trump’s speech Friday to the group was like a series of greatest hits from his campaign rallies. He reminisced about his victory in the Republican primaries.