Poll: Obama grabs lead in key swing states

A new poll released Wednesday showed Democrat Barack Obama pulling ahead of Republican opponent John McCain in the key swing states of Ohio, Florida and Pennsylvania, as their vice presidential running mates were sequestered in preparations for a much-anticipated debate. In a separate poll by The Associated Press and GfK, Obama surged to a seven-point lead, 48-41 percent, nationally - a dramatic shift from an AP-GfK survey that gave McCain a slight edge nearly three weeks ago. But since the presidential election is won on a state-by-state basis rather than a nationwide popular vote, Obama's lead in the swing states in a survey by Quinnipiac University may be more telling. The Quinnipiac survey over the weekend showed Obama's support had jumped to 50 percent or above in the must-win states, reflecting voter preferences after he and McCain held their first presidential debate last week.