A fired-up President Barack Obama has persistently attacked Republican challenger Mitt Romney in a critical debate, offering a striking contrast from his listless performance two weeks ago that appeared to damage his re-election prospects.
Mr Obama blasted Mr Romney's economic plans as damaging to the middle class and accused him of flip-flopping on issues such as energy and gun control.
He appeared angry - a rare emotion to see in the famously cool Mr Obama - when Mr Romney, a former Massachusetts governor, criticised his response to the deadly attack that killed the US ambassador to Libya and three other Americans at the US Consulate in Benghazi last month.
He pointedly told Mr Romney that any suggestion that his administration "would play politics or mislead when we've lost four of our own, governor, is offensive. That's not what we do".
The stakes of the town hall-style debate at Hofstra University, just outside New York, could not have been higher. With just three weeks to go before Election Day, the race is locked in a dead heat and many Americans are already casting ballots in states that allow early voting.
The open-stage format, meant their physical encounters crackled with energy and tension, and the crowd watched raptly as the two sparred while struggling to appear calm and affable before a national television audience of tens of millions.
It is not clear whether the debate will help Mr Obama regain the momentum he lost after his poor performance in the October 3 debate, which helped fuel a rise in opinion polls by Mr Romney. But his forcefulness was bound to cheer supporters disheartened by his previous performance.
Mr Romney also gave his supporters reasons to cheer. He appeared confident and comfortable, as he had been in the first debate, and aggressively returned Mr Obama's fire. He said the middle class "has been crushed over the last four years", and that 23 million Americans are struggling to find work.
Mr Romney also repeated a pledge to declare China a currency manipulator on his first day in office. "We can compete with anyone in the world as long as the playing field is level. China's been cheating over the years" by holding down the value of its currency and stealing intellectual property," he said.
Mr Obama told Mr Romney that "you're the last person who's going to get tough on China". He has charged that Mr Romney made money from companies that outsourced jobs to China while running the private equity firm Bain Capital.