San Francisco - At the height of the US election campaign in 2008, the Republicans tried to tarnish Barack Obama by calling him "the world's biggest celebrity," and comparing him to the likes of Paris Hilton and Britney Spears.

One year after the election, and America's first black president is still the world's biggest celebrity.

Widely admired at home and abroad, the winner of the Nobel Peace Prize enjoys influence that spreads far beyond the political realm, and puts even the Hiltons and Spears of the world to shame.

Though his popularity ratings may have slipped from an all-time high, there's still no doubt that Obama, ably assisted by First Lady Michelle Obama, still brings a distinct brand of cool to the often stultifying executive branch.

From culture to social values, Obama is already one of the most influential presidents in US history, according to David Halle, a professor of sociology at the University of California at Los Angeles, where he heads the LeRoy Neiman Centre for the Study of American Society and Culture.

"Obama is the ideal American icon," says Halle. "He represents the dream of the self-made man and, together with his wife and kids, the notion of the ideal nuclear family."

That helps explain why even 12 months after his election, the faces of the first couple seem to gaze down at you from everywhere.

On the eve of the election anniversary, Michelle Obama graced the cover of Glamour magazine in a dazzling red dress, while giving a typically down-to-earth interview in which she offered dating advice. She also appeared on the cover of The New York Times magazine for a story in which she opened up about the problems the first couple have experienced during their 17-year marriage.

The president, himself, has appeared on so many magazine covers that the media trade group Editor and Publisher had to invent a special Obama category in its magazine cover-of-the-year competition.

The Obama magic endures largely because of their attempts to minimize the personal impact of their celebrity and behave as a normal couple - albeit one living within the constraints of the presidency.

Observers have noted that since his election, Obama has purposely tried to restrain his rhetorical flourishes, as though he wants people to concentrate on his words rather than how he says them.

"He tones down his speeches. He may be the world's biggest celebrity and most powerful man, but at the same time he has tried to avoid the celebrity status," says Halle. "Americans don't really like a grandstander."

Halle is not surprised that Obama is often compared to another young, idealistic president, John F Kennedy, and says that after a year he is living up to that comparison.

"Everyone seems to agree that they are widely perceived as cool and refreshing," Halle says. "They both enjoy the same cachet."

Whereas JFK had to break the religion barrier to become the first Roman Catholic president, Obama has been forced to deal with being the first black president, and he has conducted that issue with aplomb, says Halle, by elegantly avoiding to be drawn into racial arguments.

But author Wendy Sachs says the JFK comparison only goes so far.

"While the Kennedys ushered in elegance and the Clintons brought youth, the Obamas have all of the exotic elements of modern-day celebrity intrigue," she noted on the Huffington Post under the headlined: The first couple - like us only better.

"They are the quintessential power couple. Parents of young children, they are attractive, athletic, romantic, charismatic, exotic, and trying to save the world one organic garden at a time."

Most impressive to veteran Obama watchers is the first couple's awareness of being watched the whole time, combined with the almost preternatural gift of behaving naturally, as though there are no cameras present.

"That allows them," Halle said, "to set powerful examples about model behaviour that resonate across the country and the world." (dpa)