By DAVID ESPO and ROBERT FURLOW
CHARLOTTE, N.C. (AP) - His re-election in doubt, President Barack Obama conceded only halting progress Thursday night toward fixing the nation's stubborn economic woes but vowed in a Democratic National Convention finale, "Our problems can be solved, our challenges can be met."
"Yes, our path is harder _ but it leads to a better place," he declared in a prime-time speech to convention delegates and the nation, blending resolve about rescuing the nation from near economic catastrophe with stinging criticism of Republican rival Mitt Romney's own proposals.
Widely viewed as reserved, even aloof, Obama acknowledged "my own failings" as he asked for a second term, four years after taking office as the nation's first black president.
Citing progress toward recovery, he said, "After a decade that was defined by what we bought and borrowed, we're getting back to basics and doing what America has always done best: We're making things again."
"Four more years," delegates chanted over and over as the 51-year-old Obama stepped to the podium, noticeably grayer than he was as a history-making candidate for the White House in 2008.
First Lady Michelle Obama and the couple's daughters, Malia and Sasha, joined the president on stage in the moments after the speech, followed by other family members and Vice President Joe Biden and his wife. Strains of "Only in America" filled the hall as confetti filled the air.
Obama's speech was the final act of a pair of highly scripted national political conventions in as many weeks, and the opening salvo of a two-month drive toward Election Day that pits Obama against Romney, the former governor of Massachusetts.
Not only economic proposals will settle a tight contest for the White House in a dreary season of economic struggle for millions, but also campaign cash.
There, Romney holds an advantage for sure. His campaign has purchased about $4.5 million in television advertising for the next several days, according to officials who track such spending. Obama, by contrast, emailed a fundraising appeal to supporters two hours before his convention speech.
Biden preceded Obama at the convention podium and proclaimed, "America has turned the corner" after experiencing the worst economic crisis since the Great Depression.
Obama didn't go that far in his own remarks, but he said firmly, "We are not going back, we are moving forward, America."
With unemployment at 8.3 percent, the president said the task of recovering from the economic disaster of 2008 is exceeded in American history only by the challenge Franklin Delano Roosevelt faced when he took office in 1933.
"It will require common effort, shared responsibility and the kind of bold persistent experimentation" that FDR employed, Obama said.
In an appeal to independent voters who might be considering a vote for Romney, he added that those who carry on Roosevelt's legacy "should remember that not every problem can be remedied with another government program or dictate from Washington.
He said, "The truth is, it will take more than a few years for us to solve challenges that have built up over the decades."
The Romney campaign was dismissive as Democrats completed their convention.
"Americans will hold President Obama accountable for his record _ they know they're not better off and that it's time to change direction," Matt Rhoades, the challenger's campaign manager, said in a statement.
In the run-up to Obama's speech, delegates erupted in tumultuous cheers when former Arizona Rep. Gabrielle Giffords, grievously wounded in a 2011 assassination attempt, walked onstage to lead the Pledge of Allegiance. The hall grew louder when she blew kisses to the crowd.
And louder still when huge video screens inside the hall showed the face of Osama bin Laden, the terrorist mastermind killed in a daring raid on his Pakistani hideout by U.S. special operations forces â(EURO)" on a mission approved by the current commander in chief.
The hall was filled to capacity long before Obama stepped to the podium, and officials shut off the entrances because of a fear of overcrowding for a speech that the campaign had originally slated for the 74,000-seat football stadium nearby. Aides said weather concerns prompted the move to the convention arena, capacity 15,000 or so.
Obama's campaign said the president would ask the country to rally around a "real achievable plan that will create jobs, expand opportunity and ensure an economy built to last."
He added, "The truth is it will take more than a few years for us to solve challenges that have built up over a decade."