Mourning's Miami Heat teammate, Shawn Marion, has met McCain many times, when the latter attended games of Marion's former team, the Phoenix Suns, and called him "a real cool guy." But he was moved by Obama's speech on race in March in Philadelphia in response to the Jeremiah Wright controversy, and "the way he addressed every point head-on and told you the reason why this person thinks that way. If you sit there and really listened to that speech, you have to believe in that man." They have since met at a Miami Beach fundraiser, and made plans to play two-on-two.

"It's a free country, you can do what the hell you want to do," Marion said. "It's everybody's choice to make. I'm not saying I'm out here, rioting, yelling 'Go Obama' or any of that stuff. But at the same time, if somebody asks me, we debate about stuff."

The debate, in some locker rooms, is a start.

"I don't know if this is a trend, this might just be a one-time deal," Dreier said. "But once people get involved in politics, they tend to stay in politics."

Dreier has some thoughts on why athletes have tended to stay out. Naturally, economics have played a role. (Wizards guard Gilbert Arenas recently told the Washington Post that he wasn't planning to vote, due to his concern that both presidential candidates would take more of his taxes.) But Dreier also points to sports unions, which are not part of the traditional labor movement of endorsing candidates and encouraging members to support politicians. Athletes are on their own, and the current climate doesn't support their activism.

"That's the incredible hypocrisy of the owners," Dreier said. "They are completely intertwined with the political world. They bring politicians to the games, put them in the owners' box. Professional sport team owners are among the most politically involved businesspeople in the country. They want to maintain the Congressional exemption from antitrust law, and they also want subsidies for stadiums and for parking. And then they discourage their players from exercising their free speech rights and their rights as citizens."

After the start of the Iraq War, Dreier interviewed NBA players who told them that their coaches had advised them not voice their views.

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"It's peer pressure to shut up because (management) doesn't want the fans to get their loyalties screwed up because of political differences between players and fans, and between players and other players," said Dreier, who suspects that owners would be more tolerant of athletes expressing conservative opinions.

Activism can be particularly perilous for professional team-sport athletes, who face crowds, as well as in locker rooms, of contrary thinkers, night after night. There are exceptions. NBA players Etan Thomas and Steve Nash have spoken out against the Iraq War, with Nash wearing a T-shirt that said "No War: Shoot for Peace" at the 2005 NBA All-Star game.

Ira Newble asked fellow NBA players (including James, who declined) to sign a petition targeting China for its role in the Darfur humanitarian crisis. MLB pitcher Jeff Suppan taped an advertisement in Missouri in 2006 expressing his opposition to stem-cell research. MLB slugger Carlos Delgado refused to stand for the National Anthem in protest of the United States' use of Vieques, Puerto Rico as a bombing target practice facility.

Generally, it has been more common to see athletes in Olympic and/or individual sports taking a stand on a politically-charged issue or a hotly-contested race. One recent case: Joey Cheek, a gold-medal speedskater in 2006, donated his $25,000 award to refugees from Darfur. He lost his visa and was banned from attending the 2008 Beijing Olympics as a spectator.

Some Olympic federations, like Great Britian's, have reportedly discouraged athletes from activism. Would it matter? John Hoberman, a sports historian at the University of Texas, says "my general take on this has been that 99 percent of high-performance athletes stay away from political involvement." He attributes that primarily to self-absorption, due to the rigors of training and the allure of celebrity.

Ali trained rigorously and was a worldwide celebrity. Yet the former Cassius Clay still protested the Vietnam War, suffering the consequences: scorn in many circles, and lost years during the prime of his career.

Will we see another Ali?

"No," Hoberman said. "For one thing, the '60s are gone. I remember them, I was there."

Angelo Dundee was with Ali, serving as his trainer.

"Everybody tried to copy, but they couldn't," Dundee said. "He was one of a kind. They tried to follow suit, but they didn't know how. His was a simple, sincere thing. Nobody has the zetz that this kid had. That was him. He was for real."

Ali apparently feels the same way about Obama:

He posed with Obama on a 2007 cover of Vanity Fair magazine, and was in the audience in August when Obama addressed the Democratic National Convention.

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