U.S. President Barack Obama aggressively challenged Republican candidate Mitt Romney on jobs, energy and Libya in their second debate on Tuesday as the Democrat tried to reclaim the momentum in a tight White House race.

Obama was much sharper and more energetic than in their first debate two weeks ago, when his listless performance was heavily criticized and gave Romney's campaign a much-needed boost.

Outside the Newseum, a news museum in Washington, D.C., voters shared their thoughts on the debate. Washington resident Bob Massa said the president had an improved showing in round two.

Washington resident Tom Flynn said he was impressed by both candidates.

Atlanta, Georgia resident Joan Daigle was disappointed with the second of three debates and wanted more specifics from the candidates.

Both candidates roamed the stage to talk directly to the questioners. At times they circled each other warily at center stage like prize fighters, talking over each other and bickering frequently about the rules and who had exceeded their time.

Romney confronted Obama face-to-face at one point to ask repeatedly if licenses and permits for energy drilling on federal land had been reduced during his administration.

The newspapers featured headlines like "Face off gets Testy" and "Obama and Romney spar in feisty town-hall debate" -- as the debate had veered away from normal polite decorum.

Washington attorney Emily Beline was not bothered by the bickering.

Romney's strong performance in the first debate helped him reverse his slide in the polls, and recent surveys have put the race for the White House at a virtual dead heat just three weeks ahead of the November 6 election.