A Quinnipiac University poll released today shows Sen. John McCain in a statistical tie with Sen. Barack Obama in the crucial battleground state of Pennsylvania.

Obama still leads in Pennsylvania, 48 percent to McCain's 45 percent, but that is withing the poll's statistical margin of error, so the race is essentially tied in the Keystone State, according to Quinnipiac.

The Quinnipiac University Polling Institute measured boosts for McCain in Pennsylvania, Ohio and Florida since the announcement of Alaska Gov. Sarah Palin as McCain's running mate.

According to the poll, McCain leads Obama in Florida by a 50-43 percent margin. In Ohio, Obama leads by a 49-44 percent margin.

"Republican Vice Presidential nominee Sarah Palin apparently is attracting white women likely voters to Arizona Sen. John McCain, helping him pull away from Illinois Sen. Barack Obama in Florida and narrow the gap with the Democrat in Pennsylvania, even as he is slipping slightly in Ohio," according to a press release issued by Quinnipiac University pollsters.

The release also notes that "No one has been elected President since 1960 without taking two of these three largest swing states in the Electoral College."

With Florida looking safe for the GOP, a win in Ohio or Pennsylvania by McCain could tip the election to the Republicans.

Since Aug. 26, McCain's support among white women is up four percentage points in Ohio and five points in Pennsylvania, and dropped two points in Florida, where it was high to start, the release says.

"White women, a key demographic group in any national election, appear to be in play, with some movement towards Sen. McCain in Pennsylvania and Ohio," said Peter Brown, assistant director of the Quinnipiac University Polling Institute. "Obviously Gov. Sarah Palin is having the impact that Sen. McCain hoped when he selected her."

To read the full poll results, visit the Quinnipiac University Polling Institute Web site.