It was probably his last hurrah. When Sen. Edward M. Kennedy took the stage at the Democratic National Convention on Monday, it was for what likely was his final appearance. His name alone has become the cue for an ovation from Democrats when they convene every fourth year. So it was Monday night, but with an edge of sadness. The senator from Massachusetts is suffering from brain cancer. After surgery,chemotherapy and radiation, he had kept to himself, his family and his sailboat in Hyannis Port, but for a brief appearance in the Senate to cast a decisive vote for Medicare legislation July 10. Until the convention, where a video tribute was already scheduled for Monday evening, Kennedy flew to Denver on Sunday, and went from the airport to a hospital for a check on his condition. His doctors were said to be worried about exposure to crowds because of the frailty of his immune system. Kennedy told the Democrats that “nothing, nothing is going to keep me away from this special gathering tonight.” Kennedy has been at every Democratic convention except two in the past 48 years. He is a politician who has reveled in the crowds, conventions and campaigns, to become, at 76, almost a symbol of his party. It is a story line akin to Edwin O’Connor’s classic novel of Boston politics, “The Last Hurrah,” about the final campaign of an aging politician. He spoke for seven minutes Monday night, his voice firm, his wave familiar. He told cheering ...