There used to be an expression, widely (if quietly) murmured among people after an unfamiliar figure passed, a coded but persistent inquiry:

What nationality is he?

The question wasn’t at all about its literal meaning; nobody was suggesting the stranger had anything but a U.S. eagle on his passport. It was a question about ethnicity, a comment that the individual didn’t seem to fit into any of the standard boxes – a situation almost as uncomfortable at the time as fitting into the wrong box.

The question doesn’t get asked so much anymore, partly due to politeness – or at least social pressures – and partly because these days the answer is likely to be too complicated to whisper.

And now we have a Democratic presidential candidate for whom it’s not only a multiple-choice question, but a multiple-choice answer. Barack Obama’s Kenyan-Kansas background stretches across the diversity boxes of most job applications, and even lets him campaign as the favorite son of three different states: Illinois, where he rose through the African American politics of Chicago’s South Side; Hawaii, where he grew up in the country’s only majority nonwhite state; and his grandparents’ birthplace of Kansas, where he was welcomed home although he’d never been there before running for president.

The public puzzling over his nationality is largely limited to Fox News, and to some other people who think Obama is simultaneously a militant liberation theology Christian and an undercover Muslim.

This is a dazzling achievement for Obama, and for his ability to glide through widely different situations and societies and connect with them. But in 2008, he’s also gliding through a considerably different society, which today provides a whole other reason – as if we needed one – to think about Tiger Woods.

Woods has been for a decade a national hero with an ancestry that makes him a one-man demographic pie chart. He once told Oprah Winfrey – who somehow keeps coming up in this context – that he was “Cablinasian” (Caucasian-black-(American) Indian-Asian), a word that fortunately never caught on but demonstrates his ability to soar over all classifications.

This wasn’t always a given. After Woods won his first Masters in 1997, giving him the right to pick the menu for the next year’s dinner, one older golfer joked they might be eating fried chicken. These days, as Woods moves toward becoming the first billion-dollar athlete, nobody makes ethnic jokes about him; when the globe’s champion product endorser is Cablinasian, racial jokes about it are about as funny as the Chinese trade surplus.

People don’t think of you as a mix of different things when you’ve proved you’re one of a kind.

But Woods’ changing the game is about more than his becoming a multicultural multimillionaire. It’s the style he shares with Obama, the laid-back cool over the searing intensity, the serene figure who brings his comfort level with him, who assumes the top is where he belongs. Woods may not have Obama’s Harvard Law cred, but he did have two years at Stanford before he left to make more money than any Stanford graduate – OK, not counting Nike founder Phil Knight.

It’s the confidence that decisions about where you belong are yours to make, not anybody else’s. Coming out of his mixed background, Obama identified himself as African American and rose through an atmosphere of black politics and black churches – at the same time teaching at the University of Chicago law school. Coming out of an even more mixed background, Woods identified himself his own way, and calmly makes his living in what may be the whitest environment in America – big-ticket country clubs.

And when he goes out into a different atmosphere, it’s likely someplace like Thailand or Dubai.

The possibilities of politics are shaped by culture – and in the United States, culture is what people see on their television set every weekend.

Truly talented politicians can help make their own moment, and Barack Obama has made one at a time when most people didn’t see it. But it’s a different moment than if he’d been running for president in 1996, before Tiger Woods spent a decade preparing the course.

David Sarasohn is an associate editor at The Oregonian of Portland, Ore. E-mail davidsarasohn@news.oregonian.com.