WASHINGTON — It has been a punishing month of bad food, airplane air and hoarse vocal chords. And Barack Obama isn't even on the ballot today.

The popular Illinois senator has barnstormed the country on behalf of Democratic gubernatorial and congressional candidates, one of the A-list political celebrities of the 2006 campaign season. Other big draws: President Clinton, Sen. John McCain, R-Ariz., and former New York Mayor Rudy Giuliani.

They ain't doing it for the frequent flier miles. These headliners bring glitz to otherwise ho-hum rallies and help dazzle donors out of millions of dollars. They earn the gratitude of future officeholders and get to know thousands of voters.

That's all very useful, given that these noncandidates might run for president in two years — or, in Clinton's case, is married to a 2008 hopeful, Sen. Hillary Clinton, D-N.Y. Giuliani spent the closing days in Iowa, New Hampshire, Michigan and South Carolina. All three states have Republican candidates on the ballot this year, and will host crucial early primaries in 2008.

"You're building up chits," said Illinois Rep. Rahm Emanuel, chairman of the House Democrats' campaign committee, who has summoned Obama, Clinton and others to appear on behalf of his candidates. "Everyone wants to say that they got out there and put some skin in the game, and contributed to a big win."

As of last night, when McCain returned to Arizona to campaign for Sen. Jon Kyl, he had attended 346 events and raised more than $10.5 million on behalf of Republican candidates.

Clinton's November schedule was packed with 21 events, including two rallies for his wife, who is expected to easily win a second Senate term today. The former president hit 100-plus events in 31 states for this election cycle, raising more than $33 million from Democratic donors. He taped 100 prerecorded campaign calls and filmed numerous television and radio ads. Last night, Clinton hit a rally in Alexandria, Va., with Senate candidate James Webb.

But Obama, who was born in Honolulu and graduated from Punahou School in 1979, might be the biggest attraction. Despite just two years on the national stage, Obama has generated rapturous enthusiasm among Democrats, and has said he is considering a presidential run. His success on the campaign trail in recent weeks has added to his cachet.

The Obama blitz started Oct. 5 with a fundraiser in New York City for the state's congressional candidates. The next day, he flew to Florida for a rally and fundraiser, then moved on to Kansas City, Minnesota and Ohio. By Oct. 13, he had held fundraisers for all the Senate Democratic candidates, collecting $2 million.

The freshman senator paused in the middle of the month for book-related events, then raced through Massachusetts, Pennsylvania, Arizona, Colorado and Washington state. Obama spokesman Robert Gibbs estimates Obama has visited all the main Senate battlegrounds at least three times. Another mainstay is Massachusetts, where Obama was an early supporter of Democratic gubernatorial candidate Deval Patrick, who is favored to win, and who, like Obama, is African-American.

At a Democratic rally in Norristown, Pa., he received rock-star treatment when he took the stage to tout the state's congressional candidates. In an audience of 1,000, people waved copies of his new book and angled for his autograph. One cried "We love you!" as Obama came into view.

"I love you back!" Obama responded.

He gave the same speech he has delivered at dozens of similar rallies, explaining how Americans can have "the audacity of hope" to change their lives and those of others. That's also the title of his latest book, published Oct. 17.

The crowd ate it up. Dianne Wills, a Norristown resident and a Republican, said after the rally she would vote Democratic this year after hearing Obama and other speakers. "It convinced me that my choice is right," Wills said.