A Quinnipiac University poll released Tuesday reports Barack Obama now has a 15-point advantage over John McCain in Pennsylvania, a dramatic swing in Obama's favor the poll credits largely to the country's financial crisis, the declining popularity of GOP vice presidential nominee Sarah Palin and Obama's debate performance.

The Democratic presidential nominee is up 54 percent to 39 percent over his Republican opponent in the Keystone State, the poll reports. It sampled voters from Sept. 27 to Sept. 29, the three days after Friday's first presidential debate. 

A Quinnipiac poll taken before the debate showed Obama up only six percentage points -- 49 percent to 43 percent -- over McCain.

Fiften points is by far the largest margin shown between the two candidates by any poll in the Keystone State, considered critical to both candidate's chances this fall. All of the polls, however, have shown the senator from Illinois increasing his once slim lead over McCain since the onset of the country's financial crisis. 

The poll showed Obama gaining similar leads since the debate in other battleground states. It reports Obama is up 8 points in Ohio and Florida.

"Pennsylvania is back in its role as the most Democratic swing state of the 2008 election, mainly because voters believe Obama will do a better job handling the economy," said Clay Richards, assistant director of the Quinnipiac University Polling Institute.