NELSON DIAZ'S red cheeks flank a mustache, under twinkling brown eyes. His body is no longer svelte as when he played baseball, which helped rescue him from darkness.

He's overcome many handicaps, including being born to a single mother who lived in public housing in Harlem and feeling like an outsider.

That was mostly because he didn't speak English until the third grade, partly because of bouts with asthma and partly because, "I grew up in a black community and I had to justify that I was a 'brother,' if you know what I mean."

His mother, Maria, fled Puerto Rico in shame after being impregnated by a married man. Diaz, 67, was born in New York's Bellevue Hospital and likes to explain, with a grin, that Bellevue is best known as a mental hospital.

He has been a special assistant to Vice President Walter Mondale, general counsel to HUD, Philadelphia city solicitor, Common Pleas judge, administrative judge - and employed by more top-shelf Philadelphia law firms than I can name. Now the kid from Harlem wants to be mayor of his adopted city.

An admitted poor student with "behavior problems," one positive influence on Diaz was his baseball coach, Leroy Otis, who had played in the Negro Leagues.

Diaz, who says he was a "pretty good" second baseman, played for Otis from age 10 to 17. He learned teamwork, practice and persistence, and his grades went from D to A.

Diaz says he was the first Puerto Rican to earn a law degree at Temple, he was the first Puerto Rican admitted to the Pennsylvania Bar Association. At Temple he founded the Black Law Students Association (there were nine blacks, no other Puerto Ricans), he later ran the Spanish Merchants Association and, as administrative judge, he says, he saved the city $100 million during 10 years by slashing patronage. He has organized, he has led, but usually like-minded people.

Liberalism - pro-choice, anti-gun, pro-union, anti-stop-and frisk, pro-gay - is the template of his life.

I am talking with Diaz, plus some of his family members, in the Trolley Car Diner on Germantown Avenue, not far from his Chestnut Hill home. His mood is as light as the eggs he is eating.

In walks Estelle Richman, the dynamic managing director under Ed Rendell. It's all hugs and smiles, but when I ask Richman if she is voting for Diaz, she says she's undecided between Diaz and another. Who? She won't say.

Could be Jim Kenney, because Diaz and Kenney are battling for the progressive vote. Pro-charter schools Anthony Hardy Williams won't get it, neither will pro-death penalty Lynne Abraham, nor pro-business Doug Oliver. Diaz disagrees, saying he doesn't see the race as left/right.

Diaz has no big endorsements, but says some will be announced soon and "you will be surprised." His communications guy, Barry Caro, says they never discuss finances. (Usually a bad sign.)

I ask Diaz if he's a millionaire.

Across the table, his second wife, Sara, a regional administrator for the General Services Administration, says, "Honey, will you let me in on that?"

Diaz laughs, says no, but, "I am not poor. I can afford my style of life," which includes the three-bedroom Chestnut Hill home and a Brigantine shore house.

I talk money because to become a candidate, Diaz resigned - permanently, he says - from the board of Exelon, where he could have remained until 76. Counting salary and perks, he's turned his back on $3 million. That speaks to his values.

A long shot, he's running out of love for Philadelphia and his passion for public education, which laid the foundation for his success. His three now-grown children all are public-school grads.

He'd dump the School Reform Commission and restore local control. Since the mayor can't do that, he will ask the mayor's two appointees, plus the governor's three appointees, to vote to dissolve the SRC. Diaz says Gov. Wolf "wants to do it."

The governor may want local control, "but he has not endorsed a specific plan," according to spokesman Jeff Sheridan.

Diaz would shift the property-tax burden from homeowners to commercial real estate and replace the city wage tax with a progressive income tax. The latter would require a constitutional change, something the GOP state Legislature would not approve.

Although he has been a public servant, both paid and unpaid through 45 years working in Philadelphia's communities, Diaz has never run for office before and had to be prodded.

One man holding a sharp stick was former City Councilman Angel Ortiz, even though they rarely were political allies. Ortiz cites Diaz's intellect, resume and devotion to education, but concedes that Diaz needs "an historic" Latino turnout to win (from a community with a history of low turnout).

One Latina vote he won't get is that of 7th District Councilwoman Maria Quinones-Sanchez, whose opponent he endorsed. (Diaz withdrew the endorsement last week when the opponent was portrayed as a wack job.)

In the 2007 five-way mayoral primary, Michael Nutter won with 106,805 votes. Diaz thinks that's a reachable number in another low-turnout primary.

If he triumphs, he will become Philadelphia's first Hispanic mayor. That would be quite an achievement for a kid born to a single parent in Harlem.

Phone: 215-854-5977

On Twitter: @StuBykofsky

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