CHICAGO (AP) — Leaving his re-election prospects in the hands of voters, President Barack Obama congratulated rival Mitt Romney “on a spirited campaign” and declared he’s “confident we’ve got the votes to win.”

After closing down his campaign late Monday with a nostalgia-filled rally in Iowa, Obama went back to exhorting his supporters during a Tuesday morning visit to a campaign office near his South Side Chicago home. He called volunteers in neighboring Wisconsin.

Obama was greeted by thunderous applause from about two dozen volunteers, many with tears streaming down their faces. Removing his suit coat, he sat down to make calls. “Let’s get busy,” he said.

“Hopefully we’ll have a good day,” he told a woman in one call. “Keep working hard all the way through.”

Speaking to reporters, Obama said that after all the ads and electioneering “it comes down to one day” and declared that “a source of great optimism.”

After offering congratulations to Romney, he added: “I know his supporters are just as engaged, just as enthusiastic.”

Obama was spending Election Day in his hometown of Chicago, making his last appeals to voters in a round of satellite interviews with TV stations in swing states rather than a final flurry of campaign rallies.

The president headed into Election Day locked in a close race with Romney, according to national polls. But he appeared to have a slight edge in some of key battlegrounds that will decide the contest, including Ohio, Iowa and Wisconsin.

Obama spent Monday night at the home where he lived with his family before moving to the White House.

There was no traditional Election Day photo of Obama casting his ballot Tuesday because he voted in Chicago last week, part of his campaign’s efforts to promote early voting. First lady Michelle Obama voted by absentee ballot.

One tradition Obama will keep, however, is an Election Day basketball game.

In 2008, Obama played basketball with aides before winning the kickoff Iowa caucuses. The president and his aides decided to make the games an Election Day tradition after they lost the next contest — the New Hampshire primary — on a day when they didn’t hit the court.

“We made the mistake of not playing basketball once. I can assure you we will not repeat that,” said Robert Gibbs, a longtime Obama aide who joined the president on the road for the campaign’s waning days.

The president planned to have lunch and dinner at his home but would spend other parts of the day at a downtown hotel, where he would be joined in the evening by family, friends and aides to await the election returns.

He was expected to speak — delivering either a victory or concession speech — at his campaign’s election night party at McCormick Place convention center.