With his Republican rivals vanquished, Mitt Romney is focusing on the battlegrounds that will decide the 2012 election, with a new poll Thursday showing he has pulled even with President Barack Obamain two key swing states.

"We're starting the general election, and at least in Ohio and Floridawe're starting where they are basically dead even," Peter Brown, assistant director of Quinnipiac University Polling Institute, told reporters upon release of a survey showing Romney bouncing back in two of three key swing states.

With November now six months away, focus has intensified on about a dozen states that experts say hold the keys to the White House in 2012.

They include Colorado, Michigan, Nevada, New Hampshire, North Carolina and Virginia, and both the president and Romney, the presumptive Republican nominee, have spent considerable time in several of them this year.

In the third state in the poll, Pennsylvania, Obama has opened up an eight-point lead, considerably stronger than his three-point margin from the group's survey five weeks ago, thanks to enthusiastic support for the president among women voters.

But with Quinnipiac showing Obama's leads in Ohio and Florida having eroded to the point where they are now too close to call, "that's a pretty good indication of the likely tightness of the race," Brown said.

No candidate in the past half century has won the White House without carrying at least two of the three states, and the president and his rival will likely play cat-and-mouse across Florida, Ohio and Pennsylvania -- as well as other prize battlegrounds -- in the coming months.

Obama has already traveled to Florida and Ohio four times each this year.

On Saturday he'll visit Ohio yet again, having chosen the Midwestern state as well as hotly contested Virginia as the locations of his first official campaign rallies of his re-election bid.

The two rallies will take place almost six months to the day before Obama asks voters to give him a second term despite the still stuttering US economic recovery.

Republican National Committee chairman Reince Priebus told reporters that despite officially kicking off his reelection bid Saturday, Obama has been campaigning for months.

"The president claims that he's kicking off his campaign in Ohio and Virginia this weekend, but I think we all know that he's been campaigning on the taxpayers' dime for over a year now, and we have a complaint that has been filed," Priebus told reporters.

On Thursday Romney was campaigning in Virginia, where he was joined by congresswoman Michele Bachmann, a former rival for the Republican nomination, who is now endorsing Romney.

"This is the last chance we have to keep America from going 'forward,' over the cliff, as governor Romney said, and restore the values of prosperity and freedom," she said in a statement, poking fun at Obama's new campaign slogan "forward."

Americans, she said, "can vote for more of Barack Obama's transformation of America, with more joblessness, higher energy prices, fewer opportunities for our children, more government controls, bailouts, and failed economic policies, or they can vote for a new vision of prosperity and liberty."

Republican leaders in swing states said they expect Obama will encounter plenty of November hostility from voters swept up by the rhetoric of the "hope and change" candidate four years ago, but brought down by economic woes.

"Voters have realized President Obama is out of his league and his agenda is just wrong for America,"Ohio Republican Party chairman Bob Bennett said.

"He's made our problems worse, so even with all the advantages that an incumbent president always has at his disposal, he's weak and he's running scared."

According to Quinnipiac, voters in Florida and Ohio say Romney, an ex-governor of Massachusetts and multi-millionaire investor, would do a better job with the economy, while Pennsylvanians are divided.