Senator Eliot Shapleigh - El Paso, Texas

Dolores Huerta, co-founder of United Farm Workers, urged Latinos last week to vote for Sen. Hillary Rodham Clinton.

Politics is full of theater, but few were quite prepared a week ago when state legislator and corporate lawyer Rafael Anchía burst into a reggaetón chant at a rally for his presidential candidate: Sen. Barack Obama.

The chant – part reggae, part hip-hop – hit the right chords with many in the Dallas crowd of 500.

¿Como se dice? ¿Como se llama? Obama. Obama." Or: "What's his name? How do you say it? Obama. Obama."

It addresses the obvious for Mr. Obama: Many Latino voters are only beginning to learn his personal story as an immigrant's son and his positions on issues.

Latino voters matter like never before, especially in Texas. They make up a quarter of the Texas electorate and are about 3.6 million strong. Sen. Hillary Rodham Clinton is thought to have a strong edge with the group leading up to the March 4 Democratic primary, though many Latinos, particularly younger voters, seem to be giving Mr. Obama a serious look.

Mr. Obama will face voters like Jesse García, 36, and his 65-year-old mother, Lupita, who seem unshakeable in their loyalty to Mrs. Clinton.

"Hispanics are brand-loyal, and Hillary is tested," said the Dallas man. "Barack is courageous ... but Hillary's time is now. Who can say she is not about change? How can you say that ending 220 years of male domination in the White House is not change?"

His mother back in Brownsville, where support for Clinton is particularly strong, is equally emphatic.

"He has a brain," she said, "but not as much as Hillary has."

Still, Mrs. García said she worries about "machos" of the Rio Grande Valley.

"I'm afraid that the men won't give her a chance," she said.

Differing focus

Other Latinos – many of them under 29 – are undecided. They make up nearly a third of Latino voters in Texas, versus 24 percent for all Texas voters, according to the nonpartisan Pew Hispanic Center.

Hammy Ibarra, a 19-year-old naturalized U.S. citizen from Mexico and first-time voter, attended an Obama rally Wednesday that drew at least 17,000 to Reunion Arena.

"I've never seen an African-American achieve something like this," Ms. Ibarra said. "I need to see what he offers Hispanics."

And Mr. Obama's campaign team seems to be banking on that squishy concentration of indecisive voters, of all ethnicities and even political parties.

While Mrs. Clinton has focused hard on cities along the Texas-Mexico border, Mr. Obama has gone to larger urban areas, where he can capture votes from all demographic groups and prime the pump in areas with larger pools of delegates.

Lionel Sosa, a marketing executive who's worked on Bush campaigns, contends that brand loyalty and personal contact are key aspects of selling products, or candidates.

Then trust builds, Mr. Sosa said.

"You can get the Latino to like you and to trust you ... to solve any problem that comes along," Mr. Sosa said.

But Mr. Obama's done a weak job in that regard, he said. "That is the reason that Obama is behind Hillary in attracting the Latino vote. He has not had the time to make that bond. You have to bond with the Latino."

Growing response

Mr. Anchía acknowledges Mrs. Clinton's strong lead among Latinos.

Two weeks ago, the ratio was 70-30 in her favor. But, in part because of Spanish-language campaign ads, that margin is closing. Latinos in the Super Tuesday Democratic primaries showed a marked preference for Mrs. Clinton, supporting her over Mr. Obama 63 percent to 35 percent, according to a report last week by the Pew Hispanic Center.

"I have heard a whisper number that he is already at 38 percent," Mr. Anchía said. "He needs a good amount of Latino vote to win. He is not wanting to cede any ground, or any geography."

While the embrace may be slow in coming, some young Latinos are responding anyway.

A Mexican-style corrido, or ballad, launched on the Web site www.amigosdeobama.com has gone viral and is now on YouTube, encouraging Latinos to vote for Mr. Obama. The video shows cooks, mechanics, and business people shouting "Viva Obama!" as Mariachi Aguilas de Mexico croons "Su lucha es tambíen nuestra lucha," or "His fight is also our fight."

The video is by Miguel Orozco, the son of a Mexican immigrant, who said he wasn't affiliated with the Obama campaign but thought his Burbank-based firm Nueva Vista Media could pitch in – especially after Mrs. Clinton trounced Mr. Obama with California Latinos in early February. And it follows a reggaetón number he also produced.

Mrs. Clinton has a formidable campaign support, from former Cabinet secretary Henry Cisneros, who served in her husband's White House, to Antonio Villaraigosa, the mayor of Los Angeles, to Dolores Huerta, the co-founder of the United Farm Workers.

Last week, Ms. Huerta combed the state, rallying Latino voters in Spanish and English to go to the polls in the early-voting period, which ends Friday.

Winning the delegate game is essential to both candidates' strategy, in this tight race. And that's especially true for Mrs. Clinton, who needs a win after Mr. Obama's 11-state victory streak.

"Everyone is looking at you," Ms. Huerta, 77, told a small crowd of Clinton supporters last week. "What is Texas going to do? ... The right thing to do is to vote for Hillary Clinton."

Ms. Huerta first met Mrs. Clinton shortly after President Clinton took office in 1993 and Mrs. Clinton invited about a dozen "women of color" to visit the White House.

"No one had ever reached out to us like that," Ms. Huerta said.

Making choices

With four children, 35-year-old Theresa Urbina said she had to support Mrs. Clinton. That's why she arrived 90 minutes earlier to attend an Oak Cliff rally on Friday in temperatures that hovered around 35 degrees.

"Being a woman, I think she will put forward issues that men don't feel are important, like health care. There are times when I have to budget and not go to annual exams," the uninsured mother said.

Oscar Mejia likes Mrs. Clinton and her track record. But when the 31-year-old looks at Mr. Obama, he sees the face of his children.

Mr. Mejia, a naturalized U.S. citizen born in El Salvador, is married to a black woman. (Mr. Obama is the son of a black Kenyan and a white Kansan.) The father took his two children, 9-year-old Giovanni and 10-year-old Gianna, to the Obama rally Wednesday and then on to a Chelsea Clinton rally at a local university.

"I am still on the fence," Mr. Mejia said.