By ALFONSO CHARDY

A day after President Bush reiterated his plan to legalize millions of undocumented foreign workers, two advocates on immigration disagreed in a public debate on whether illegal migrants help or hurt the United States.

James M. Staudenraus, eastern regional field director for the Washington-based Federation for American Immigration Reform, said illegal migrants undermine America because taxpayers have to shell out billions of dollars to cover their medical care and schooling -- among other expenses.

But Randolph P. McGrorty, executive director of the Archdiocese of Miami's Catholic Charities Legal Services, said the economy benefits because immigrants pay more in taxes than they receive in services.

The debate at the Tower Club in downtown Fort Lauderdale, before dozens of Broward business and community leaders, came one day after President Bush repeated his call for temporary work and residence permits for millions of illegal migrants working in the United States.

''It is time for an immigration policy that permits temporary guest workers to fill jobs Americans will not take, that rejects amnesty, that tells us who is entering and leaving our country, and that closes the border to drug dealers and terrorists,'' Bush said in the opening paragraphs of his State of the Union speech to Congress Wednesday night.

Bush originally unveiled his temporary guest worker program in January 2004, but legislation for it has yet to be submitted to Congress.

Nevertheless, Bush's brief inclusion of his proposal in his speech signaled that immigration reform would be one of the administration's priorities in its second term.

Neither McGrorty nor Staudenraus directly addressed Bush's proposal. But in their statements they seemed to agree with Bush's contention Wednesday night that the country's immigration system needs to be fixed.

However, Staudenraus and McGrorty disagreed on how resolve the dilemma of illegal immigration.

Staudenraus said illegal workers should be strongly encouraged to leave the country by punishing employers who hire illegal migrants.

''The solution, we believe, to illegal immigration is that we go after the employers,'' Staudenraus said. ``There's a $10,000 fine. It's on the books, but no one's paying...for hiring an illegal alien and there's jail time for repeat offenders.''

Staudenraus said once employers are deterred from hiring illegal migrants, the migrants would leave in droves.

'There's nobody in serious policy circles that's going to say `Get a bunch of 747s and deport people en masse,' '' he said. ``If you secure the work place and make it almost impossible for illegal immigrants to take part in this economy, they will repatriate themselves on their own.''

McGrorty prefaced his position by saying he did not favor ''open borders,'' but his statements clearly showed he opposes the tight immigration controls Staudenraus' group favors.

McGrorty said immigrants strengthen the economy, contributing more than they receive in services.

''Rewarding people who work hard, live the American dream and contribute to our community, that's what we need to focus on in immigration reform,'' he said. ``Everyone agrees that we have to screen the bad people out, deport the bad people who are here.''

McGrorty acknowledged that illegal migrants cost taxpayers money, perhaps more than $30 billion in health care and schools, but he noted that overall the American economy receives about $110 billion in taxes from migrants.

''So it seems to me we've made $60 to $80 billion from this population,'' McGrorty said. ``They are a net contributor to our society.''

People in the audience had mixed reactions to the event, which encapsulated the broader national debate on immigration reform.

Paul Sallarulo, an investment banker with Wachovia Securities in Fort Lauderdale, said he disagreed with Staudenraus' proposal to prompt illegal workers to leave.

Sallarulo said he favored Bush's guest worker program instead.

Margaret Sanchez, chief development officer at Hispanic Unity of Florida in Broward, agreed with McGrorty's contention that the country should focus on immigrants' contributions -- ''not the negatives'' of immigration.

The debate was sponsored by the Tower Forum, a Broward business and civic organization that holds monthly debates on topical issues.