Duly noted by the media on President George Bush's trip to Florida last month: a reference to rampant prostitution in Cuba, and the four ham, cheese, and pork sandwiches he bought from the local Cuban café la Tropicana. Mr. Bush was in Tampa on July 16 for a Justice Department conference on human trafficking-a presidential visit, not an official campaign stop. But paying attention to Cuban-Americans in a swing state during an election year inevitably received more attention than his message.

That was a pity to some conference attendees, who have appreciated Mr. Bush's opposition to human trafficking. The practice is modern-day slavery, involving the sale of 600,000 to 800,000 people a year across international borders into forced prostitution or labor. About 80 percent are women, and 70 percent of them are funneled into the sex trade. "Human life is a gift of our Creator," Mr. Bush told the audience. "It should never be for sale."

Most nonprofit groups fighting against trafficking praise Mr. Bush for his gung-ho leadership against the scourge. But is it enough of an election issue to persuade anti-trafficking warriors on the left to support him? The answer depends on how much credit they think goes to stiff laws, and how much to Mr. Bush.

"Trafficking is an issue that everyone recognizes is a priority with the Bush administration," said Derek Ellerman, executive director of Polaris Project. The group is nonpartisan, although he describes most of its employees as "leftists." "Whatever other disagreements we have with the Bush administration, they've done well on that." Nonetheless, Mr. Ellerman thinks Democrats might do just as well. "I think it's hard to say; there's never been a Democratic administration with this kind of law."

The law is the Trafficking Victims Protection Act, signed by President Clinton in the twilight of his second term in October 2000. It created tougher penalties for traffickers, increasing prison terms for slavery from 10 to 20 years. The law also required the State Department's Trafficking in Persons office to submit an annual report that ranked countries in three tiers according to how actively they fight trafficking.

Those in the lowest tier, making little effort to prosecute offenders, risk U.S. economic sanctions. Last September Mr. Bush sanctioned North Korea, Cuba, and Burma. Since 2001, when the first report appeared, roughly 20 countries per year have landed in the lowest tier. The threat of sanctions has been enough to spur several to the negotiating table. Last year, 24 countries adopted "new, comprehensive" anti-trafficking laws, according to State's 2004 report.

With the law in its court, the Bush administration has been able to charge 149 traffickers since 2001, three times the number prosecuted in the previous three years. Number of convictions: 94, twice the number secured over the previous three years. The United States has also provided $295 million for anti-trafficking efforts in 120 countries.

Ann Jordan, Global Rights' anti-trafficking director, says Mr. Bush's successes are a natural outgrowth from the Clinton administration's foundational efforts: "It's not because of who he is-there's more money in it. We have organizations that are funded now." More progress is "just natural."

Still, Mr. Bush has done well to press the issue in the international community, said Michele Clark, co-director of Johns Hopkins University's Protection Project. Last September he spoke before the United Nations General Assembly, and devoted several minutes of his speech to human trafficking, the first time a U.S. president has addressed the issue on an international platform. Ms. Clark says the speech helped define trafficking for countries still hesitating over how to approach the problem, which some nations confuse with issues of illegal migration.

Ms. Clark, a conservative, argues that Mr. Bush's leadership has also been essential in ensuring the U.S. anti-trafficking efforts actually took off. "The legislation signed by the former president could have just remained on the books," she said. "As for anything, the earliest years for new legislation are very important. They do require leadership from the top in order to gain momentum."

Human-rights activist Aaron Cohen, though he's not a conservative, also praises Mr. Bush. He calls himself and his clients liberals. His clients have included U2 lead singer Bono and pop star Ricky Martin, whom he helped gain access to Washington heavyweights when they began charity work on debt relief and slavery. "If George Bush does well in trafficking, I'm going to say so," he said. "It's not an opinion."

As important as fighting human trafficking is, Ms. Jordan doesn't believe Mr. Bush's performance is enough to sway fellow activists' votes. She says the Bush administration has laid sufficient groundwork for future leaders. "To me it's not so much if you're a Republican or Democrat, but if you will make this a high priority."