“Democrats should be very nervous,” said Bill Burton, a former White House spokesman and senior strategist at Priorities USA, which is raising millions of dollars for the 2012 election. “They need to put on their war paint and get ready for what is going to be a very difficult battle. Unless activists really engage and recognize the stakes of this fight, it’s going to be impossible for the president to win.”…

“The mine hasn’t collapsed, but the loss in New York is definitely a dead canary,’’ said Democratic strategist Craig Varoga, president of an independent liberal group called Patriot Majority. “It is going to be a very, very difficult election, and it is time to wake up and be bold…. We have to face reality and the fact of how unhappy and scared people are.’’

Obama’s advisers are contemptuous of the suggestion that the bottom is falling out from under the president. In their view, his approval ratings, while down slightly, reflect a Democratic base that is strong…

“It would be an understatement to say that calling the next election based on a 60,000-vote turnout in a [New York] congressional race 14 months before election day is ill-advised,’ ” said Ben LaBolt, a spokesman for Obama’s reelection bid.