Hempstead, N.Y. (AP) — Republican White House challenger Mitt Romney conferred with his debate practice partner while President Barack Obama exercised before his final study review for Tuesday's debate, both hoping it would help them pull ahead in the razor-tight race.

"I feel fabulous," Obama told reporters on his way into a meeting with top aides after three days of intensive "debate camp" at a Virginia golf resort. The pressure was especially high on the Democratic incumbent after even he admitted he lost the first debate two weeks ago.

Romney smiled broadly as he exited his plane in New York, where his second chance to face off with the president was scheduled at Long Island's Hofstra University. Ohio Sen. Rob Portman, a constant companion in recent days as he played Obama in practice sessions, crouched in front of Romney's seat for much of the flight. They later joined aides in their hotel's auditorium for final preparations.

The candidates will take questions on domestic and foreign policy from an audience of about 80 of the coveted uncommitted voters whom both campaigns are so furiously courting with just three weeks left until Election Day. The town hall-style format makes it especially tricky for Obama to strike the right balance in coming on strong against Romney without turning off the audience — and tens of millions of television viewers — by going too negative.

The Campaign 2012 juggernaut has raced ahead nonetheless: Both sides have unfurled new ads, hustled at the grassroots level to lock down every possible voter, dispatched surrogates to rev up enthusiasm and kept the running mates busy raising cash and campaigning in the most hotly contested states.

Romney political director Rich Beeson laid down a marker that Romney would be victorious in one of the most aggressively fought contests — Ohio. "To be clear, the Romney-Ryan campaign will be victorious in the Buckeye State," Beeson said in a memo written with the campaign's Ohio director, Scott Jennings, arguing that several factors are working in Romney's favor there. No Republican has ever won the presidency without carrying Ohio, where polls show Obama running strong.

Arizona Sen. John McCain, the 2008 Republican presidential nominee and a top Romney supporter, wouldn't go as far as Beeson and predict a GOP win in Ohio.

"I can draw a scenario where Mitt Romney can win without Ohio, but it's a very, very difficult path," McCain said in an interview with The Associated Press while campaigning in Ohio for Romney. "And so I think the eyes of the world will be on Ohio and, from the polling that I see — and this is obviously a very dynamic situation — we could be up late."

With both candidates preparing for the debate and Vice President Joe Biden attending former Senate colleague Arlen Specter's funeral, Romney running mate Paul Ryan was the only member of either ticket out campaigning. He was taking a swing through Virginia. In an interview with Virginia's conservative radio host John Fredericks, Ryan said supporters working to get out the vote for the GOP ticket "have been just really doing the Lord's work all throughout the state."

He later campaigned in the foothills of the Blue Ridge Mountains, arriving for a Lynchburg rally in a pick-up truck with a large American flag flapping behind in the cab as AC/DC's "Rock 'N Roll Train" blared.

Ryan said the election "is about what kind of country we are going to be, what kind of people we are going to be. That's what this is about."

Romney picked up the backing of former independent presidential candidate H. Ross Perot. "We can't afford four more years in which debt mushrooms out of control, our government grows and our military is weakened," Perot wrote in an editorial announcing his endorsement Tuesday in the Des Moines Register.

Obama's campaign turned to former President Bill Clinton on Tuesday to make the case against what it says is Romney's $5 trillion tax cut. Clinton appears in a Web video for the campaign, picking apart Romney's tax plan piece by piece, saying his approach "hasn't worked before and it won't work this time."

The president's campaign says Romney hid from his tax proposal during the first debate, and pledged Obama would be more aggressive in calling out his rival's shifts on that and other issues this time around. Clinton, who has been praised by Democrats for explaining Obama's economic arguments more clearly than the president himself, appeared to be laying the groundwork in the video released hours before the second faceoff.

The president plans to cast an in-person ballot in Chicago on Oct. 25 — making history as the first incumbent to vote early. First lady Michelle Obama dropped her Illinois absentee ballot in the mail Monday. The president later joked that he appreciated her support. "Thank goodness!" he said Tuesday after his morning workout.

Obama did not respond to a question about a more serious matter developing. Secretary of State Hillary Rodman Clinton said she takes responsibility for security at the U.S. consulate in Benghazi, Libya, where four Americans were killed last month. Obama wouldn't say Tuesday whether he agreed she was to blame.

Romney pressed the White House on the matter last week after Biden said in the vice presidential debate that "we weren't told" about requests for extra security at the consulate. But State Department officials, testifying before Congress that day, said they were aware of those requests. Clinton backed up the White House's assertion that the issue didn't rise to the president or vice president's attention.

Obama's campaign, seeking to improve some of the optics that reinforced his poor performance, planned to send several elected Democratic officials to the "spin room" to speak with reporters immediately after the debate.

The campaign only had a handful of Obama advisers in the room after the first debate. Because those same advisers also had to meet with the president after the event, they showed up noticeably later than the Republican officials promoting Romney.

Their late arrival reinforced the notion of a campaign struggling to comprehend the president's lackluster performance.

Tuesday's debate audience of uncommitted voters was selected by the Gallup Organization. Moderator Candy Crowley of CNN will choose who gets to speak, after reviewing proposed questions to avoid repeats.

The final debate of the campaign will be Oct. 22 at Lynn University in Boca Raton, Fla., focusing on foreign policy.