President Barack Obama cast his re-election battle with Mitt Romney as a clash between starkly contrasting philosophies and charged that his Republican rival would hollow out the middle class in a high-stakes speech on Thursday that could set the tone for months of intense campaigning.
Standing at a podium that bore the motto "Forward," Obama accused Romney of wanting to resurrect the Republican economic policies that preceded the 2008 crisis that plunged the United States into a recession from which it has not fully recovered.
"We can't afford to jeopardize the future by repeating the mistakes of the past. Not now, not when we've got so much at stake," Obama told a crowd of 1,500 at a community college in the battleground state of Ohio.
On a day when both candidates for the November 6 presidential election spoke in Ohio, Romney struck first in a speech that ended four minutes before Obama took the stage.
"He's been president for three and a half years. And talk is cheap, actions speak very loud. If you want to see the results of his economic policies, look around Ohio, look around the country," Romney said at Seilkop Industries, a Cincinnati manufacturer.
Obama is coming off the roughest stretch of his presidency since last summer's debt-ceiling showdown and his Democratic allies worry that he could lose the election if it is simply a referendum on his efforts to boost the shaky economy.
The president faces a delicate balancing act. While he must convince voters that the economy is headed in the right direction, he cannot minimize the struggles that many continue to face. Too much finger-pointing could lead many to question whether the White House incumbent is ducking responsibility.
His approval ratings have slipped to their lowest level since January, from 50 percent a month ago to 47 percent, because of deep economic worries, wiping out most of his lead in the presidential race, a Reuters/Ipsos poll showed on Tuesday.
A Gallup poll released on Thursday found that two-thirds of Americans blame Obama's Republican predecessor, George W. Bush, for the troubled economy; only half pointed to Obama.
That may not be enough to counter a steady drip of bad economic news that has eroded Obama's standing. In a sign of continued weakness in the job market, the Labor Department said the number of Americans filing new claims for unemployment benefits rose for the fifth time in six weeks.
Europe's economic crisis, which has eaten into U.S. economic growth, showed signs of worsening.
Obama did not help his cause last week when he said the private sector was "doing fine" compared with struggling local governments.
Republicans say the remark shows he has little understanding of Americans' economic troubles. The Romney campaign kept up the pressure on Thursday with a television ad that repeats Obama's remark four times.
Obama acknowledged on Thursday that the comment was a misstep.
(Additional reporting by Sam Youngman in Cincinnati, Caren Bohan and Susan Heavey)