FORTUNE -- Even without a cape or sunglasses, Newark Mayor Cory Booker has the makings of a superhero or a rock star, maybe even a hybrid of the two.
He saved a dog from the cold, housed his neighbors after a hurricane, and shoveled a stranger's snow. He subsisted on food stamps and lived in public housing. His Twitter following is five times the size of the city he governs, and Oprah is one of his biggest fans.
There's no doubt that in Wednesday's special U.S. Senate election, Booker's celebrity translated into the 725,000 votes he received from New Jersey voters as he trounced Republican candidate Steve Lonegan by a double-digit margin.
But in assessing Booker's leadership ability, showmanship doesn't count for nearly as much. When it comes to what he's gotten done as the leader of Newark, Booker's bright spots are accompanied by a few smudges.
Booker brought new businesses, restaurants, and hotels to Newark's downtown core, but the city's unemployment rate stands at 14% -- double the national rate. Murders in the city dropped dramatically during Booker's first term, but they have inched back up since then. He's given Newark a national profile but that's a product of him spending significant time outside his city and state.
Those concerns likely weighed on the minds of the third of likely New Jersey voters who said Booker is more about self-promotion than improving Newark in a Rutgers-Eagleton Institute survey released this week.
But criticism of Booker the mayor won't dampen his future; in fact, it's what will make him a great senator.
There's a clear distinction between the personalities and leadership styles of successful executives -- like mayors and governors -- and state and federal legislators, says David Thornburgh, executive director of the Fels Institute of Government at the University of Pennsylvania. Executives are detail– and results–oriented and concerned with day-to-day operations, like whether street lights work, whether thoroughfares are cleaned, and how to fund repairs to infrastructure.
The role of a legislator, meanwhile, is oriented toward statesmanship. It's more about communication and engaging constituents on an emotional and symbolic level, says Thornburgh. See under: Booker, Cory. "He has an ear and eye for the tenor of the times," says Thornburgh. "He knows what people respond to and how he can get them excited and engaged about a particular issue."
Andra Gillespie, a political science professor at Emory University and author of New Black Politician: Cory Booker, Newark and Post-Racial America, says Booker's leadership style will translate well to the Senate because he not only has vision but knows how to get the public behind it.
The challenge will come, though, in how Booker fits his outsize charisma into the stuffy Senate chamber, where even show horses -- Ted Cruz aside -- tread lightly. "He has a national following and gets a lot of attention and media requests," says Gillespie, "There may be concern among his senor colleagues that he's being asked to speak on topics that they think they have more expertise and experience on." He may have to defer to his senior colleagues, she says.
Or, some may argue, he should soak up the Senate spotlight. An exotic dancer in Oregon isn't the only one who can appreciate a Booker charm offensive. The U.S. Congress could benefit from it too.
Interview by Geoff Colvin, senior editor at large
The world is urbanizing fast -- more than half the globe's people now live in cities. That fact makes the
management of urban areas a critical challenge and mayors more important than ever. Few mayors are attracting as much attention as Newark's Cory Booker, leading a city with a 40-year reputation for blight, crime, and poverty. Already well known, Booker became far more famous MOREFortune Editors - Nov 16, 2010 11:46 AM ET
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