Poll shows Obama up big in Pa.

More than four months before the presidential election, U.S. Sen. Barack Obama (D-Ill.) is beating U.S. Sen. John McCain (R-Ariz.) by a healthy 12 points in Pennsylvania, according to a poll released this morning.

The Quinnipiac University poll of swing states also found Obama leading in Florida and Ohio. But his most comfortable margin at the moment is clearly in Pennsylvania, where pollsters found him enjoying strong support from women and young voters, not to mention overwhelming support from black voters.

It was the first time Obama led the poll in all three states.

"Finally getting [primary opponent] Sen. Hillary Clinton out of the race has been a big boost for [Obama]," said Peter Brown, assistant director of the university's polling institute.

"Sen. Obama is certainly not out of the woods, but these results are a good indication that he enters the summer slightly ahead in the race to be the next president."

The only group McCain carried in the poll in Pennsylvania was men, by a narrow margin of 47 percent to 45. One good sign for McCain was that 73 percent of respondents said his age would not be a factor in their vote.

But in an indication of the uphill battle he may face, pollsters found that the long primary season had "hardened the battle lines," with 75 percent of voters saying they had already decided who would get their vote.

The poll surveyed 1,511 likely Pennsylvania voters from June 9-16, with a margin of error of +/- 2.5 percent.