EL PASO – Hillary Rodham Clinton kicked off her campaign in Texas with a rally attended by 10,000 enthusiastic supporters, staking her claim to this must-win state and leaving behind eight straight losses to Barack Obama.

Like William B. Travis, this is her line in the sand. Only this time, she is hoping the Latinos will be on her side.

"I can't think of any better place to start our campaign for Texas than right here in El Paso," Mrs. Clinton told the raucous crowd. "We're going to sweep across Texas in the next three weeks, bringing our message about what we need in America."

With her opponent clearly on a roll, Mrs. Clinton is pinning her hopes on a solid victory in delegate-rich Texas to take back the upper hand in the race for the Democratic nomination. And she began with a flourish, launching new ads to appeal to Hispanics and scheduling a robust campaign day today throughout South Texas.

She came in like a rock star, with music blaring in a blackened University of Texas at El Paso basketball coliseum lit by a thousand cellphones. Her 25-minute speech ended in a flurry of red, white and blue confetti.

But her talk was sprinkled with a feeling of homecoming and reminders of her links to the state and its border. She learned political organizing in 1972 by registering voters in El Paso and South Texas for George McGovern.

"I remember coming here 35 years ago," she said. "I met some of the best friends I've ever had in my life."

The New York senator said she warmly remembers being welcomed into homes, eating great food, listening to wonderful music "and registering a few voters."

"Here I am in El Paso, Texas, asking the children of those voters to vote for me for their future," she said.

The ties that she hopes will bind deep into the heart of Texas include serving as first lady of neighboring Arkansas and having maintained touch with Latino residents, who are likely to make up one of every three Democratic voters in the March 4 primary.

Henry Cisneros, one of her leading supporters, said he first met Mrs. Clinton when her husband was governor and she invited the then-San Antonio mayor to tour Arkansas health facilities.

"I was impressed with her dedication then, and it has become firmer, more focused and more effective over the years," said Mr. Cisneros, who will tour the state for her.

Former Texas Land Commissioner Garry Mauro, a top state organizer for Mrs. Clinton, said Tuesday that the Democratic contest is a race to reach 2,025 delegates, and, "you have to do very well in Texas to do that."

He said she is well ahead here with "a 36-year head start." But because of Mr. Obama's recent string of victories, "we're going to be throwing everything at the race, including the kitchen sink."

With 228 delegates at stake in Texas, Mr. Mauro said, Mrs. Clinton is making her stand in the Lone Star State and in Ohio. She is expected to open more than 20 offices across Texas and dispatch her husband across the state.

Mrs. Clinton began the quest in El Paso, ignoring her opponent's expected sweep of the three Potomac contests Tuesday. Instead she turned to the large crowd, mostly female and Hispanic, where she hoped her future would begin.

"More and more the Hispanic vote is important," said 18-year-old Vanessa Juarez, a high school student who expects to cast her first presidential vote for Mrs. Clinton. "If she can get it here, she can get it in a lot of other places."

Along with the launch of a Spanish-language ad, Nuestra Amiga (Our Friend), Mrs. Clinton will continue her tour today in McAllen, Corpus Christi and San Antonio.

"When she goes to South Texas, she's going home," Mr. Mauro said.

The Hispanic vote has been a bedrock of her victories, along with women and working-class voters. Mrs. Clinton has consistently outpolled Mr. Obama among Hispanics by 2-to-1 ratios.

It is a point Mr. Mauro was pleased to point out, and he suggested that Texas, with its large Latino population, will be a difficult place for Mr. Obama to make inroads.

"Obama has a real problem in a big, diverse state that's reflective of the national population," Mr. Mauro said. "Apparently, he has institutional problems with Hispanics."

Josh Earnest, an Obama spokesman, said the Illinois senator will work hard to introduce himself to the Latino community. "We'll certainly talk about Senator Obama's experience of organizing in the Hispanic community in Chicago," as well as his proposals on health care and education, "to solve the challenges we face that would benefit the Hispanic community."