BY BETH REINHARD, CASEY WOODS AND JOSE PAGLIERY

As Democrat Barack Obama headlines a rally Wednesday during his second campaign swing through Florida in as many weeks, he faces a challenge in the diverse battleground state: winning over Hispanics.

He's 10 percentage points behind Republican John McCain among Hispanics in Florida, according to a Miami Herald/St. Petersburg Times/Bay News 9 poll released Sunday that showed a tight race overall. McCain is favored by Hispanics 51 to 41 percent in the survey. The poll's margin of error for the Hispanic voter numbers is 10.6 percentage points.

A Mason-Dixon poll released Tuesday showed McCain leading by 6 percentage points among Hispanics; that lead is within the margin of error.

The gaps exist despite a statewide surge in Democratic registration among Hispanics and Obama's promise to spend a record-setting $20 million on Hispanic outreach nationwide. Tuesday, the campaign released ads on Spanish-language television and radio in Florida that depict McCain as oblivious to the millions of Americans without health insurance or jobs.

McCain also released a Spanish-language ad last week hammering Obama for his willingness to meet with leaders such as Venezuelan President Hugo Chávez.

RELATED RACES

Obama's current drag among Hispanics could hurt the Democratic Party's chances of unseating three South Florida Cuban-American Republicans in Congress -- Lincoln Diaz-Balart, Mario Diaz-Balart and Ileana Ros-Lehtinen -- said Roland Sanchez-Medina, vice president of the Cuban-American Bar Association.

''I don't think the Obama campaign is doing as good a job as they can in getting his message out to Hispanic voters,'' said Sanchez-Medina, who supports the Democratic nominee. "I'd like to see the campaign dedicate a lot more time to Florida.''

Obama's camp pointed to a Sept. 10 poll by the New Democratic Network that found Hispanic voters in Florida evenly split between the nominees. According to the poll, Obama ran strong among Hispanics in Colorado, New Mexico and Nevada -- other key swing states with large Spanish-speaking populations but few Republican-leaning Cuban Americans.

`FIGHT HARDER'

''The Hispanic vote is going to be competitive, and we are going to fight harder than any other Democrat has in Florida,'' said Miami consultant Freddy Balsera, who advises Obama on Hispanic outreach. "It's going to be a very issues-based plan that draws the distinctions between Obama on healthcare, the economy and tax cuts for working-class families versus McCain.''

Since winning the Hispanic vote in 2006, Florida Democrats have been predicting a sea change in which older Cuban Americans will be outnumbered at the polls by younger Cuban Americans and newer arrivals from Latin America who are more concerned with healthcare than their homelands. Democrats also have been counting on a backlash among Hispanics to rhetoric from conservative Republicans over immigration.

But Republicans say Obama hurt his chances with some Hispanic voters by saying he would be willing to meet with antagonistic government leaders in Cuba and Venezuela. A new Spanish-language ad depicts Hugo Chávez ranting against ''filthy Yankees'' and asks: "Did you see who Obama wants to talk with?''

The ad will be effective among Venezuelans, as well as in the Cuban and Colombian communities that share a hostility toward Chávez, said Republican state Rep. Juan Carlos Zapata, who is Colombian American.

''Obama is talking about talking to bad guys, and a lot of people are here in Florida because they left those bad guys, people like Chávez and Castro,'' Zapata said.

Obama's opposition to a free trade agreement with Colombia has also turned off some Hispanic voters who have been successful in international trade, Zapata said.

Interviews with voters and community leaders suggest Obama's challenge is less about foreign policy and more about who he's not. Many Hispanic voters felt more comfortable with Hillary Clinton -- a name brand in politics -- than the junior senator from Illinois.

''When Obama put Biden on the ticket and not Hillary, he definitely lost his calculator,'' said Republican pollster Kellyanne Conway, who helped conduct the Miami Herald poll.

Mason-Dixon pollster Brad Coker said his survey found a clear divide in the Hispanic community, with overwhelming support for McCain among Cuban Americans and strong backing for Obama among other Hispanic voters. But the McCain supporters are more likely to go the polls because they've been in the United States longer, Coker said.

EXPERIENCE CONCERNS

One such voter is Ruben Maranges, 79, who was born in Cuba but has lived in New York and Miami for four decades. He said of Obama: "I don't think he has the experience to lead this country. They need to understand the economy, foreign affairs.''

Rhadames Peguero, executive director of the Allapattah-based Dominican American National Foundation, pointed to another issue that may lurk behind Obama's failure to capture part of the Hispanic vote: racism. On a recent day at The Home Depot in Hialeah, where Peguero lives, he overhead a man say to his companion, ''No voy a votar por ese negro,'' -- ``I'm not voting for that black man.''

''It's not the majority, but there are some racist feelings in the community,'' Peguero said.

As the nation's economy spirals downward, Obama's poll numbers have been creeping up. His new Spanish-language television spot derides McCain for saying last week in Jacksonville that ''the fundamentals of our economy are strong.'' McCain later said he was talking about the resilience of the American workforce.

McCain and Obama also have dueling ads on immigration, even though they were on the same side of the landmark legislation that would have allowed illegal workers to earn citizenship.

McCain is running spots that accuse Obama of trying to destroy the legislation with ''poison pill'' amendments, though the GOP's conservative wing largely doomed the effort.

Obama is also airing a misleading ad that tries to link McCain to anti-immigrant remarks by talk host Rush Limbaugh.

Miami Herald staff writer Mary Ellen Klas contributed to this report.