WASHINGTON (AFP) ― With polls showing Republican Mitt Romney drawing even with President Barack Obama, the incumbent heads to Florida on Thursday to court voters in one of the swing states that could determine the November election.

Florida is the largest of the dozen or so toss-up states that are drawing much of the two candidates’ attention in the 2012 race, and Obama, who has already made several campaign stops in the Sunshine State this year, is well aware that a Romney victory there could derail his re-election.

Obama will likely try to keep the focus on his rival’s record at Bain Capital, the private equity firm Romney founded and ran for several years and which has been criticized for buying firms that later shipped many of their jobs to law-wage economies like China and India.

The re-election team has also hammered Romney over his refusal to release pre-2010 tax returns, as they seek to paint the presumptive nominee as a wealthy elitist who sought to squirrel his money away in offshore accounts in Switzerland and tax havens like the Cayman Islands.

Republican senators and other senior party leaders have also pressured Romney to release more data, but the presumptive nominee has refused, saying Tuesday that opponents would only “pick through, distort and lie about” them.

Romney is a former governor of Massachusetts and a multimillionaire businessman with a huge personal fortune. He is challenging Obama on his economic record, arguing that he is better-placed than the Democrat to turn around the still sluggish U.S. economy.

A New York Times/CBS News poll showed a growing number of Americans might agree.

Although the results were within the margin of error, Thursday’s poll marked the first time Romney showed a numerical edge, with 45 percent of respondents saying they would vote for him if the elections were held now, compared with 43 percent for Obama, the New York Times said.

And it showed a key shift in respondents’ attitudes toward Obama’s ability to improve the economy, with 39 percent saying they approve of his handling of the economy and 55 percent saying they disapproved.

In a Times/CBS poll in April, when economic prospects appeared brighter, that approval rating was 44-48 percent.

But Thursday’s results come during a period of slackening U.S. job growth, with Federal Reserve chairman Ben Bernanke seeing “frustratingly slow” drops in the unemployment rate, which has hovered above eight percent for over three years.

With the economy clearly the number one issue for U.S. voters in November’s election, the trends in the country’s jobs climate could well dictate the fate of the incumbent, regardless of events such as the Supreme Court ruling that upheld his signature health care law.

Voters are turning on Obama in a key measure, according to the poll, with just 36 percent of Americans viewing him favorably, compared with 48 percent who said they do not. In April, that breakdown was 42-45 percent.

And the study showed little recent shift in attitudes toward Romney despite extensive negative advertising by Obama’s re-election campaign and extensive criticism of Romney’s business record.

There were some hopeful signs for the president, however. Respondents overwhelmingly saw Obama as the advocate for the middle class, and while 46 percent said his policies favor the middle class and poor, only 13 percent said Romney’s policies would do so.

And while over half of Obama’s supporters said they strongly supported him, fewer than a third of Romney’s supporters said the same about the Republican challenger.

An NPR poll released overnight showed that if the election were held now, Obama would edge Romney 47-45 percent, although that figure is within the margin of error.

It also showed a dead heat, 46-46 percent, in 12 battleground states, including Ohio, Florida, North Carolina and Virginia.

Obama will attend at least four campaign events on his two-day swing through Florida, beginning in Jacksonville and followed by West Palm Beach.