CHARLOTTE, N.C. – 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.