BY GAIL EPSTEIN NIEVES

Wrenched from his family and his homeland of Cuba, 15-year-old Mel Martinez wound up with a foster family in Orlando, where the mother of the house served him his first-ever peanut-butter-and-jelly sandwich and asked, ``What do you want to call me?''

''Mami?'' Martinez answered tentatively.

But Eileen Young -- who took in the frightened teen in 1962 as part of Operation Pedro Pan -- proposed using the Spanish word for aunt, tía, instead. Big tears rolled down Martinez's face.

''I realized what a relief that was,'' Young, now 79, said recently. 'Here's a young boy who, if he had to call us mami and papi, was willing to do that. His parents told him `Whatever you've got to do, do it,' and he took that to heart.''

For Melquiades Rafael Martinez, failure has never been an option.

''My parents raised me that way,'' affirms Martinez, 57, the Republican candidate for the U.S. Senate seat being vacated by Bob Graham. 'It was the idea of, `You've got to succeed, you can't fail,' and that involves sacrifices, accommodations.''

But after a bruising primary battle with his strongest opponent, former U.S. Rep. Bill McCollum, and controversial comments from his campaign since, some observers ask of Martinez's ambitions: Will he stop at nothing to get elected?

Character issues are new territory for Martinez, who cultivated a conservative, good-guy image during his years of legal, civic and political service.

His compelling life story helped: Martinez was separated from his parents for four years after leaving Cuba through Pedro Pan, the Catholic Church program that brought 14,000 unaccompanied children from the island in the early 1960s.

Thrust alone and penniless into a strange environment, Pedro Pan kids like Martinez lived in what he calls a ''sink or swim'' world filled with unfamiliar food, language and culture. Despite the trauma, a good many of them thrived and went on to great success.

Martinez's resume tracks his accomplishments: Twenty-five years as a top personal injury lawyer in Orlando, chairman of Orange County government, and secretary of the U.S. Department of Housing and Urban Development until last year.

In January, the Akerman Senterfitt law firm hired him for a salary of about $400,000 a year.

Martinez tells what he calls ''my incredible life story'' in nearly every stump speech.

It allows him to emphasize how far he has come from his poor, immigrant beginnings through a combination of smarts, hard work and networking, and it explains what he says is his prime motivation for public service: a desire to ``give back.''

''The things I've been able to do with my life, I just thank this country for just providing me the opportunity, for being the kind of place where someone can land on these shores at age 15 not knowing a word of the language and be able to develop and grow, be part of the whole,'' he told a Broward group recently.

ON CAMPAIGN TRAIL

Comfortable with public speaking after years of trial work, Martinez easily hits his major themes on the campaign trail.

Foremost is bashing his Democratic opponent, Betty Castor.

He plays up his first-name relationship with the presidential family, tossing out references to ``George and Laura.''

He stresses his bona fides as a ''compassionate conservative'' Republican who opposes abortion and gay marriage, favors tax cuts, supports the war in Iraq.

He highlights his Hispanic heritage -- one of the reasons White House strategists courted him to run so he could help the president attract the Hispanic vote. If elected, he would become the first Cuban-American senator.

Martinez's background is a big selling point in Miami-Dade County, flush with Cuban Republicans. Martinez racked up 102,441 primary votes in Miami-Dade, compared with Castor's 43,371 votes. The point spread was the largest in the state.

Martinez also appears popular with some non-Cuban Hispanics who relate to his immigrant experience.

MEMORIES OF CUBA

Get Martinez off politics to talk about his childhood in Cuba, and his whole body relaxes. The memories spill out -- of his house in Sagua la Grande surrounded by coconut and guava trees and singing tomeguines, a small bird.

Of afternoons spent fishing in his very own rowboat or traveling around to farms with his dad, a large-animal veterinarian, in their 1950 burgundy-colored Chevy.

Of special trips to Havana and Santa Clara to watch a professional baseball game -- Mickey Mantle was his greatest hero -- or to pick out a trinket at the Woolworth Ten Cent store, popularly called ``el tencén.''

''I also remember sitting at the counter eating an American-style sandwich, like a BLT, for the first time,'' he said. ``That was cool.''

SETTLES IN ORLANDO

Shipped abroad in the wake of Fidel Castro's 1959 revolution, the loving, secure childhood Martinez enjoyed had come to an end.

Martinez settled in Orlando with the Young family for his junior and senior years of high school. He lived with another family for two years while attending junior college.

Despite facing occasional bigotry, Martinez is forever grateful that he didn't wind up in Miami.

The Pedro Pan kids who settled outside of Miami ''Americanized and truly became bicultural, and I think that truly opened a lot of opportunities in life,'' he says.

Then his parents arrived with his sister, presenting a new set of challenges. Martinez became their bill-payer, their interpreter, their chauffeur, their grocery shopper.

''Mel became the father figure,'' Young recalled. ``None of this was easy.''

Martinez still considers his exile via Pedro Pan one of the most formative experiences of his life.

''I'm a no-nonsense kind of guy, bottom-line oriented,'' he says. ``I know what it's like to be poor, to want to get ahead in life, the bumps in the road because you're different from others. I know how hard it is for immigrants to make it in America.''

He has a soft spot for children, Martinez said, ``because I remember those days when I'd look in the bleachers and every other dad was there, but I didn't have my dad there. So all of those experiences, out of the hardness of all that, does come some good. It makes you who you are.''

But just who is Mel Martinez? After several mis-steps by his campaign, even some Republicans are wondering: Is this the real reflection, and is he determined to win at any cost?

''Mel Martinez is one of the more driven, fire-in-the-belly candidates that I've seen,'' said Richard Pinsky, a consultant for failed Republican Senate candidate Doug Gallagher.

After the Aug. 31 primary, Martinez expressed regret for his advertising attacks on opponent McCollum and said he had not signed off on them.

The campaign had said McCollum, a 20-year Republican congressman with a conservative record on social issues, was ''antifamily'' and pandering to the ''radical homosexual'' agenda.

The attacks cost Martinez the editorial recommendation of The St. Petersburg Times, which wrote, ``No matter what else Martinez may accomplish in public life, his reputation will be forever tainted by his campaign's nasty and ludicrous slurs of McCollum in the final days of this race.''

Then in September, a Martinez campaign statement referred to law officers involved in the seizure of rafter child Elián González as ``armed thugs.''

Again, Martinez said afterward that he wasn't responsible for the ''inappropriate'' comment.

Martinez denies that he's willing to do anything to win.

''I don't think you're any better than the means you use to achieve your goals,'' he said. ``I'm not so full of ambition that I forget ethics.''

But politics is a rough game that requires rough tactics, he said.

''Do you do an ad that's tough?'' he said. ``Of course, or else you don't win. But at any cost? No. The fact is I ran an upbeat campaign save for one mistake. I think a person ought to be judged by a lifetime, not by one event.''