James F. Kenney, a 23-year veteran of City Council and true son of South Philadelphia, rolled to an easy victory Tuesday in the Democratic mayoral primary, making him the odds on favorite to become Philadelphia's next chief executive.

Backed by an impressive coalition of organized labor, progressive groups and key African American political leaders, Kenney, 56, overcame a field of candidates that included former District Attorney Lynne M. Abraham, former Common Pleas Judge Nelson Diaz, former PGW executive Doug Oliver, former state Sen. T. Milton Street and the candidate once seen as the frontrunner - state Sen. Anthony H. Williams.

With 30 percent of the vote counted, Kenney was leading by three-to-one margin over Williams, his closest challenger. The remainder of the field trailed far behind.

Kenney was running strongly in all sections of the city, and showed remarkable strength among African American voters, a sign that Philadelphia's traditional racial voting patterns maybe eroding. That crossover vote proved decisive as a healthy margin of black voters rejected Williams, the most prominent African American in the race, in favor of Kenney, an Irish Catholic and former Mummer.

As of now, Kenney's only rival for City Hall is Melissa Murray Bailey, a 36-year-old businesswoman who ran unopposed for the Republican nomination. With Democrats holding a nearly eight-to-one registration edge, Bailey faces daunting odds if she is to become Philadelphia's first Republican mayor since 1951.

A possible third and more potent candidate is Bill Green, the former city councilman and current School Reform Commission member, who switched his Democratic registration to independent in March in anticipation of a possible mayoral run. "It's something we're looking at," Green said in an interview. "I'm not going to do any planning until after Tuesday."

The man of the moment, however, was Kenney, a passionate if sometimes intemperate son of a firefighter who learned the art of politics as a staffer of former state Sen. Vincent J. Fumo before winning a seat on Council in 1991.

Kenney earned a reputation as a maverick who, while a reliable vote on matters important to police and fire fighters, defied his conservative South Philadelphia rowhouse roots and became a progressive leader on issues such as gay and lesbian rights, immigration reform and the easing of penalties for possession of marijuana.

Kenney entered this year's race late, only after the January withdrawal of former city solicitor Ken Trujillo left a coalition of labor and business leaders without a candidate to back.

Those leaders, led by John Dougherty, the head of the powerful electrical workers union, prevailed upon Kenney to resign from Council and take a run to replace outgoing Mayor Nutter.

Kenney inherited the campaign professionals left adrift by Trujillo's withdrawal. He was endorsed by the city's municipal unions as well as the Philadelphia Federation of Teachers. Most importantly, many of the city's most influential black political leaders, including state Rep. Dwight Evans, Council President Darrell L. Clarke and Councilwoman Marian Tasco, gave Kenney their blessing.

From the start, Kenney's chief rival was always presumed to be Williams, who was counting on support from the city's black voters. Williams also had the backing of three wealthy Main Line financial traders who, like Williams, favor school choice.

Those backers put up $6.8 million in an ultimately unsuccessful advertizing campaign to elect Williams.

That effort only raised suspicions for voters such as Mount Airy resident Jane Century.

"I don't understand the logic," Century said. "But it's certainly not out of the goodness of their hearts."

Century's vote went to Kenney, who she called the "the what-you-see-is-what-you-get" candidate.

She touted his knowledge of the issues, but admitted that his connection to union leader Dougherty troubled her. Finding the perfect candidate is a futile search, Century said.

"You don't get to pick the ideal person. You get to pick from who's running," Century said.

Bridget Woodmark, a freelance artist, and her husband, Michael Ruttenberg, a lawyer, both age 76, were divided as they left the Saigon Maxim polling place in South Philadelphia.

Woodmark voted for Williams because he came across the best on television. Ruttenberg cast a ballot for Kenney, because he had ran the most effective campaign.

"I know Anthony Hardy Williams and I knew his father, and I had great respect for him," Ruttenberg said, referring to the late state Sen. Hardy Williams. "But I think Anthony got a little desperate toward the end of the campaign, and he went with attack ads."

Williams had a strong showing of support in far West and Southwest Philadelphia, parts of his senatorial district and home to Hardy Williams High Mastery Charter and the Hardy Williams Veterans Center.

For instance, there was Ella Johnson, 84, a retired school custodian who voted at Mitchell School at 56th Street and Kingsessing Avenue. "He's more for the community," she said of Williams. "Really, I voted for him because I've known him ever since he was a young boy."

But even in Williams' backyard, there were Kenney voters.

"Skin color didn't make a difference," said Elbert Drakeford, who is African American and cast his ballot at the Christy Recreation Center at 56th and Christian streets. "I voted on the issues."

Apparently he was not alone.

Staff writers Thomas Fitzgerald and Samantha Melamed contributed to this article.