As the Senate takes up immigration reform, Cuban-born Mel Martinez tries to serve as a broker to hammer out a compromise between the factions in his own party.

By LESLEY CLARK

WASHINGTON - Mel Martinez makes his case for immigration reform any way he can. The personal: A boyhood refugee from Cuba, he knows why immigrants seek out the United States.

The practical: Boom states like Florida are thirsty for labor.

And to his Republican colleagues, the Florida senator who is emerging this week as a leading voice for comprehensive immigration reform underscores the political: A contentious debate over immigration reform risks alienating the burgeoning Hispanic voting bloc his party has sought to court.

''We as Republicans need to be careful how we address this issue,'' Martinez said Wednesday at a breakfast with the U.S. Chamber of Commerce, which supports sweeping immigration reform. ``The issue has galvanized the Hispanic and Latino community like no other. There's a real political angle to this that is important to our party.''

But the Florida senator acknowledges he faces a skeptical crowd of GOP colleagues, some of whom are interested only in stemming illegal immigration through stricter border enforcement. Indeed, as Martinez motored back to the Capitol after the breakfast, Sen. Jeff Sessions, R-Ala., took to the Senate floor to suggest that ''good fences make good neighbors'' -- an endorsement of a controversial House proposal to put up 700 miles of fence along the U.S.- Mexican border.

`DISTASTEFUL'

Martinez, who says he finds some of the House bill ''distasteful,'' was undaunted. He buttonholed Sessions in the corridor after a vote.

Sessions won't discuss what was said, but he suggested that Martinez is being heard.

''The human concern that Mel has articulated so well has got to be considered,'' Sessions said. ``I don't know if Mel and I agree on all the issues, but the principle of making sure we don't terrify and upset people unnecessarily, that's got to be addressed.''

Martinez has yet to claim any public converts in a debate fraught with emotion, presidential political aspirations and polls that suggest most Americans don't want to make it easier for illegal immigrants to become citizens.

But Texas Republican John Cornyn, who supports a bill that Martinez thinks is unworkable because it would require illegal immigrants to return home before they are eligible for guest-worker status, notes of Martinez: ``I think he's causing people to think, and that's a start.''

Martinez has been working the issue since last fall, teaming up with Sen. Barack Obama. D-Ill., to push for border enforcement, but coupled with a guest-worker program that reaches out to the estimated 11 million illegal immigrants already in the United States.

'There are those in the country who feel the country is `full,' '' said Martinez, who came to the United States in the 1960s as part of Operation Pedro Pan. ``Had that been the prevailing view in the 1960s, I would not be here.''

BILINGUAL PUSH

Martinez stepped up the pace this week, taking to the airwaves in English and Spanish, and imploring his colleagues at a closed-door Republican caucus to not stop at border protection.

''I made a talk that ended up with a little applause at the end, I was glad to hear,'' Martinez said, adding that he was ``essentially calling on us to rise above the rhetoric, the passions. To look at this in a more logical way and get it done to the benefit of all Americans.''

He insists the more permissive immigration plan he backs, to give undocumented immigrants a chance at residency, does not constitute amnesty -- as many critics suggest.

It would require immigrants to pay fines and learn English before becoming citizens. And he cites figures from Florida hotels, restaurants and the tourism industry, suggesting that the state desperately needs workers.

`ONE VISION'

Martinez, the only foreign-born member of the Senate, perhaps is closer to the issue than most of his colleagues. He speaks passionately of his trip to the United States as a teenager -- and he follows Spanish-language reports of the debate.

He says that ''Sensenbrenner'' -- as in Rep. James Sensenbrenner, R-Wis., is now a household word in many Hispanic homes. Sensenbrenner is the House sponsor of a bill that would put up the fence and make criminals out of immigrants without paperwork.

Immigrants who work at the Capitol have approached him to talk about the issue, Martinez tells colleagues.

''Hearing it from the guy behind the counter, they know the name of the bills, it's what everyone is talking about in the Hispanic community,'' Martinez said. ```We've not been of one mind, of one vision. Today, on this issue, I really think we are.''

Where that leaves his divided party is unclear.

''There's no doubt it's not been well-received,'' Martinez said of the congressional debate over hardening the borders. ``But I don't know that it's lasting. It's not been helpful, it's not been the kind of thing you want to be associated with, but I think we still have a great opportunity with the final product to come out of this OK.''