Oct. 18, 2006  -- Democrat and Republican, liberal and conservative -- they've all done it. From Newt Gingrich to Bill Clinton, Nelson Rockefeller to John McCain, politicians of all stripes have upheld one of the country's not-so-proud traditions: romancing women almost half their age.

But in our current era of political correctness and lack of privacy, that behavior has come under fire, exposing lawmakers to ridicule and sometimes leading to career-breaking scandals, such as the recent congressional imbroglio involving underage pages.

So, when the news first broke that San Francisco's popular 39-year-old mayor Gavin Newsom was dating a 19-year-old model and restaurant hostess (she's since turned 20), the city buzzed with gossip -- and more than a little scuttlebutt -- about the City by the Bay's newest power couple.

First, the San Francisco Chronicle reported that Brittanie Mountz, who played lacrosse for Sonoma State University, had suddenly changed her age on her MySpace page from 19 to 26. Then, the paper's political columnists scooped that Mountz, who is under the legal drinking age in California, was pictured holding a glass of wine at a recent gala that Newsom attended. The mayor's spokesman quickly responded that Newsom has never provided Mountz with alcohol, adding, "If she was drinking, the mayor didn't notice."

But is the city bothered by the mayor's May-October relationship? Not exactly. Some longtime observers expressed concern that the romance, along with his support for gay marriage, could prove to be a political liability for Newsom, who's considered one of the young stars of the Democratic Party and is expected to run for national office in a few years. (His approval ratings hover above 80 percent, and he appears to be cruising to re-election in next year's mayoral race.)

"Everyone expects him to have this big political career, but he makes a lot of bad choices," says one editor at a local paper. "[Newsom's ex-wife] Kim was always putting her foot in her mouth and now he's dating this girl who's barely out of college. He lets his hormones take over."

Indeed, Kimberly Guilfoyle Newsom embarrassed the mayor when she made some crude comments about her husband's physical endowment and sexual orientation at a gay rights fundraiser in 2004.

And there were some annoying headlines when his last girlfriend, "CSI: Miami" star Sofia Milos, took him to an event sponsored by the Church of Scientology last March. Plus, Newsom's phone number showed up on Paris Hilton's buddy list when her Sidekick messaging device was hacked in 2004.

But in tune with the free-thinking spirit of the city, most San Franciscans don't seem bothered by Newsom's new romance. "I haven't heard anyone say anything negative about the young woman he's seeing," says Chronicle gossip columnist Leah Garchik. "It's a live-and-let-live city, and we have a young handsome mayor. More power to them."

After all, the city's previous mayor, Willie Brown, had a child out of wedlock with one of his aides -- and he's still regarded warmly by the San Francisco community.

Even some of the mayor's enemies think his romance is just fun gossip. Jack Davis, a political consultant who's been actively courting former 49ers president Carmen Policy to run against Newsom next year, seems blasé about the relationship. "Of all the cities in the world, San Francisco would be the last place that would raise an eyebrow," says Davis. "If he was French-kissing a colleague, it might raise an eyebrow. ... It might be an issue on a national stage, but certainly not locally."

And why would a young woman be interested in dating a man almost twice her age, even if he is the mayor? "What makes him more appealing is how much power he wields," says Carol Berkin, a political historian at Baruch College in New York, who points out that Confederate leader Jefferson Davis was 38 when he married a 17-year-old girl.

"What gets the heart beating fast is that he's got a chauffeur or that he's the top man in San Francisco," Berkin adds. "This is what women have been conditioned to find attractive."

And San Francisco seems to be full of young women who would happily trade places with Mountz. Beth Spotswood, a 28-year-old development director, started a blog almost two years ago devoted to chronicling her crush on Newsom. And what does Spotswood find so special about Newsom? "Other than the fact that he's a flawlessly dressed, breathtaking man?" she gushes. And then there's Stefania Pomponi Butler, who recently posted high school yearbook photos of "Mayor McHottie" on her CityMama blog, asking her readers, "Am I turning into a crazy stalker or what?"

The only time the mayor's budding romance seemed to bother people in San Francisco was when it was revealed that Mountz was a registered Republican. "How dare he?" asked one city official. "He knows how to pick 'em. You can count the young female Republicans in this town on one hand."