LAS VEGAS -- The vast majority of Nevadans have never participated in the complicated process the state's political parties use to apportion presidential delegates for their national conventions.

And in Spanish, there's not even a word for "caucus."

Latinos -- who make up a quarter of Nevada's population -- are being heavily wooed by leading candidates as voters prepare to line up tomorrow at more than 1,700 meeting sites.

"A lot of people don't even know what a caucus is. They don't know what's going on," said Celeste Barajas, 23, whose family owns Lindo Michoacan, an upscale Mexican restaurant in largely Hispanic northeastern Las Vegas, where New York Democratic Sen. Hillary Rodham Clinton recently held a roundtable discussion.

The Republican race is more or less settled. Only former Massachusetts Gov. Mitt Romney, who can count on backing from a sizable Mormon population, has actively campaigned in the state.

Democratic leaders are spearheading a major campaign to reach voters who speak little or no English, using television, radio and newspaper advertisements. They've also held dozens of practice caucus sessions.

"Nuestro caucus," our caucus, is an ad that plays repeatedly on Las Vegas radio stations in between the bouncy Norteno songs popular in northern Mexico.

The party even created a local soccer team: Los Democratas. Ruben Kihuen, an assemblyman who was born in Mexico and is a prominent supporter of Mrs. Clinton, was a team captain.

Headphones for instantaneous Spanish translation were distributed at an appearance by Illinois Democratic Sen. Barack Obama at a high school last night.

"Nevada was chosen as an early caucus state because of our diversity," said Kirsten Searer, a party spokeswoman. "We're doing everything we can to reach out to the Hispanic community."

About 9,000 people participated in the 2004 caucuses, which took place after Massachusetts Sen. John F. Kerry had already secured the Democratic nomination.

This time, party leaders are expecting 40,000 participants, although Senate Majority Leader Harry Reid, a Nevada Democrat, has said he thinks as many as 100,000 will come out.

"I myself will feel very embarrassed if we don't turn out in big numbers on Saturday," said Eddie Escobedo, a supporter of Mrs. Clinton and publisher of El Mundo, one of southern Nevada's largest Spanish-language newspapers. "We're hoping to make a small dent in the political scene."

There are more than 600,000 Hispanics in Nevada. But only about half are eligible to vote.

Leaders of Culinary 226, the largest union in the state, have been trying to persuade legal residents to apply for citizenship, so they play a larger role in state and national politics. Hispanics make up nearly 45 percent of the union's 60,000 members, including many workers in the massive hotels and casinos along the Las Vegas Strip. In the last year alone, 2,000 participated in the "citizenship project."

"We have a lot of Latino members who are delighted to vote," said Chris Bohner, a spokesman for the union, which this month endorsed Mr. Obama.

To accommodate some hotel and casino workers, the Democratic Party has designated nine "at-large" caucus sites in some of the most exclusive casinos on the Strip. That has sparked a fight between 226 and another major union, the Nevada State Education Association, which last week sued to block the at-large sites, arguing that they unfairly favor Culinary members. But a federal judge dismissed the case yesterday.

"We think the [teachers] union was being used by the Clinton campaign," Mr. Bohner said.

Officials with the Clinton campaign had said they were staying away from the issue. Yet it could be a significant blow to the former first lady, who has been very popular among Hispanics and had been courting the Culinary union.

A national survey released last month by the Pew Hispanic Center found that 59 percent of Latinos who are registered voters and identify as Democrats favored Mrs. Clinton, while just 15 percent supported Mr. Obama. New Mexico Gov. Bill Richardson, who is Hispanic, received 8 percent.

Mr. Obama's support may have increased after his victory in the Iowa caucuses and Mr. Richardson's recent decision to withdraw from the race.

Of the 30 Iowa precincts that are majority Hispanic, Mr. Obama won half, according to Shannon Gilson, a spokeswoman for his Nevada campaign.

"If Latino voters examine my track record, I think they'll feel enormous confidence that I will be a strong advocate on behalf of equal opportunity and fairness," Mr. Obama told the Las Vegas Sun this week.

Both Mr. Obama and Mrs. Clinton last year voted for the Senate's failed immigration reform package, which would have created a path to citizenship for approximately 12 million undocumented immigrants in the country while enhancing border protection.

Democratic former North Carolina Sen. John Edwards has the backing of several unions with large Latino memberships, including the United Brotherhood of Carpenters and Joiners of America.

Mrs. Clinton has received the endorsement of many in Nevada's small but growing Latino political community.

"Experience. That's the bottom line. Experience," Adriana Martinez, who served as chairwoman of the state Democratic Party from 2003 to 2006, said of her decision to support Mrs. Clinton.

A sampling of about a dozen local Latino voters found that many agree.

"She's smart," said Gerardo Lopez, 44, a naturalized citizen born in Durango, Mexico, who has lived in Las Vegas for 18 years. "She understands the problems with immigration."

Mr. Lopez, a manager at Lindo Michoacan, met Mrs. Clinton when she came to the restaurant last week. (In the typical Las Vegas style of excess, the bar there boasts 800 bottles of tequila.) Hundreds of people pressed inside the small space to see the senator as she ate "pollo sarandeado" (grilled chicken breast) and posed for photos with workers in the kitchen.

Of more than 80 employees at the restaurant, most of them back Mrs. Clinton, he said. He and Ms. Barajas, the owner's daughter, could name only one Obama supporter.

Across the street at La Bonita Market, there were few customers or employees who were eligible to vote, but some said the hype surrounding the caucuses was making them want to become involved.

"I have to start to do it," Mario Duenas, a Mexico City native who has lived in the United States for 25 years, said in Spanish, describing the process to become a citizen. "Those who vote are the ones who are going to govern."