The upper deck was mostly empty when President Barack Obama closed out the campaign season Sunday afternoon with a rally on the campus of Cleveland State University. His aides looked grim, fiddling with their BlackBerrys as Democratic National Committee staffers scurried to get a crowd estimate from fire marshals: 8,000 in a hall built for 13,000. It was a fitting coda to the waning days of a brutal election season for the president and his party. Obama spent the final, frenetic weekend of Midterms 2010 hopscotching the East Coast and Midwest trying to close the 'enthusiasm gap' in key states. The task required him, at times, to confront the minor indignities that come with being demoted from rock star to mortal politician. He traded high-dollar fundraisers for free rallies; in his hometown of Chicago on Saturday night, 35,000 turned out to see him in an outdoor park. He doffed his tie and shouted himself hoarse, tweaking his standard stump speech -- the one with the laugh lines about Republicans 'drinking a Slurpee' and driving the economy 'into a ditch' -- into a more affirmative, upbeat vision of why voters should elect Democrats, and not just reject Republicans. He suffered hecklers. He persevered. 'We've seen a lot of enthusiasm, but it's going to be tight,' the president told reporters Sunday morning during an impromptu breakfast stop at a Chicago cafeteria. He ordered pancakes, eggs and turkey sausage 'to go.' Another stop -- Cleveland -- was on the agenda. 'These are close races,' Obama said. 'It's true here, it's true in Ohio, it's true in every state where we're competing. And obviously the other side is enthusiastic. We've got to make sure our side is too.' But with dissatisfaction running high on the left, Obama also encountered hostility from his own side. In Bridgeport, Conn., on Saturday, the president was in the thick of his usual riff on Republicans ('They realize, 'Boy, we really made a mess of the economy.'') when a chant came from the top of the arena: 'Fund global AIDS!' He had heard it before; AIDS protesters have been dogging him for weeks. 'You've been appearing at every rally we've been doing,' Obama said, sounding irked. 'And we're funding global AIDS. And the other side is not. So I don't know why you think this is a useful strategy to take.' The hecklers, dressed in Yale and Harvard T-shirts, persisted; the crowd looked perplexed. For a moment, the rally seemed to spin out of Obama's control. He tried pleading: 'Now look, let me just understand -- everybody -- we're all right. Come on, guys.' He tried cajoling: 'Hey, listen up, listen up, listen up, listen up.' Finally, the intruders were silenced -- when the police escorted them out. They were, as it turns out, just the kind of voters Obama is trying to reach -- university students with a streak of idealism. One of them, David Carel, a 19-year-old Yale student, said afterward that he would have voted for Obama in 2008 had he been old enough to do so. Now, he is not so sure. 'What he does over these next two years is going to determine my thoughts,' Carel said. The two-day, four-state weekend swing took Obama to Philadelphia, Bridgeport, Chicago and Cleveland -- cities in states that are critical to Democrats' prospects. In each, Democrats are in tight races. Obama used his closing argument to remind voters that it was time to 'finish what we started,' a phrase his wife, Michelle, has been using in her own stump speech. Harking back to his own election, he conceded that times have changed. 'Some of the excitement of Inauguration Day -- you know, Beyonce was singing and Bono was up there and everybody was feeling good -- I know that good feeling starts slipping away,' he said Saturday night in Chicago. The crowd interrupted him, shouting, 'Nooooo!' The Chicago homecoming was clearly a treat for the president -- 'I'm going to sleep in my own bed tonight!' he announced. Throughout the weekend, Obama found comfort in familiar things. A cocoon of his closest advisers -- David Axelrod, his senior adviser; Jim Messina, the deputy White House chief of staff; Patrick Gaspard, the political director; Reggie Love, his longtime assistant; and Marvin Nicholson, his trip director -- spent the weekend with him aboard Air Force One. 'You know,' Axelrod said, 'he is a very centered person, he understands the ups and downs of these things. I don't think he's consumed by reflections on what this means for him. I think he's very focused on making the case and helping folks get elected.' Obama took on the tenor of a salesman at times, making a pitch wherever he went for Democrats to knock on doors and make phone calls, and for voters to get to the polls -- as early as possible. In Philadelphia, he implored a crop of Democratic canvassers to knock on '20,000 doors.' Here in Cleveland, he came prepared with directions to the nearest polling spot. 'There is early voting just a few blocks from here,' the president announced, 'so you can go right after this rally if you haven't voted. Because if everyone who fought for change in 2008 shows up to vote in 2010, we will win this election. I am confident of that.' As a politician, Obama has always done best with his back against the wall. Still, this weekend, a sense of inevitability was in the air. Looking around the half-empty arena in Cleveland, the rally's organizers said the president was competing with forces beyond him -- church, football, Halloween. When Axelrod was asked Saturday night if the White House believes Democrats can keep control of the House, he did not say yes. He said, 'I think we've got a great shot.' 