As he retreats to Camp David for a final summer getaway, President Barack Obama is mapping out a post- Labor Day plan to regain the political offensive, including a private meeting next Tuesday with House Speaker Nancy Pelosi and Senate Majority Leader Harry Reid . After taking office with a two-thirds approval rating, Obama has watched it slip closer to 50 percent. Over the summer, he lost ground on the health care debate and other aspects of his crowded agenda, and his dealings with Congress — controlled by fellow Democrats — also worsened as worries increased about losses in next...