Conservative activists say President Bush should push forward with his second-term mandate ratified by 59 million voters on Election Day, including a constitutional amendment banning same-sex "marriage." On issues ranging from tax cuts to Social Security to abortion, Republican stalwarts yesterday said the president should stick to his winning campaign agenda, rejecting calls to "reach out" to the Democratic minority in Congress. "Democrats still don't get it," said Grover Norquist, president of Americans for Tax Reform. "What they want Bush to do -- change the goals he told voters he'd get done if they gave him a second term --...