EL PASO — Alice Rosas' decision to back Hillary Clinton in the Texas presidential primary comes down to dollars and cents — specifically, the $617 monthly health insurance premium the single mother shells out for her and her teenage son.

The 54-year-old Hispanic is part of the fastest-growing demographic in the nation, and is the type of voter along the border and across South Texas that Clinton is banking on to help her win on Tuesday.

But the sections of 1,250-mile-long border that Clinton traversed when she was registering Hispanics for George McGovern in 1972 is a vastly different place today. The county that includes the largest city on the Texas side, El Paso, has nearly doubled its 1972 population to 736,000 in 2006, according to the Census Bureau.

Since 1990 alone, the population of the 14 Texas border counties has grown by 48 percent, with most of the growth concentrated at either end of the border.

But the number of Hispanics who vote has lagged far behind the population increase they have fueled.

In El Paso County, for example, voter registration grew by 86 percent between the presidential election years of 1988 and 2004, while the number of actual voters increased by only 42 percent, according to University of Texas at El Paso Professor Gregory Rocha. Turnout dropped from almost 60 percent to 46 percent during the same period.

Clinton will learn Tuesday whether the rapidly growing number of Texas Hispanics translates into ballot box muscle.

Given that her opponent, Sen. Barack Obama, has made a concerted effort to draw Hispanic support of his own in South Texas, it also remains to be seen whether she will dominate that vote the way she did in California, where exit polls showed that Hispanics turned out for "Hilaria" at a rate of nearly 3 to 1.

But even if she does, that leaves a third, more basic question: Will it be enough?

The mathematics of the state's Democratic delegate apportionment process do not favor her.
Rapid growth

Rosas lives in the 79936 ZIP code, which El Paso demographer Jesse Acosta says is one of the fastest-growing in the nation. Everywhere in the sprawling east side area, swaths of sun-baked West Texas desert are being transformed into strip malls, schools, and $80,000 starter homes.

And with thousands of new people arriving each year, the role of Hispanic voters in South Texas and the border, where Latinos make up more than 80 percent of the population, is prime steak in the red-meat battle between Clinton and front-runner Obama.

"We're the last stronghold," said La Joya Mayor and longtime Rio Grande Valley powerbroker Billy Leo, referring to the nearly half-million votes in play in the Valley. "We just need the turnout. The closest thing for us to ever having a Latino president is Hillary Clinton."

Die-hard Democrats like Leo — his father's gravestone carries the missive "an uncompromising Democrat" — realize all too well how much Hispanics matter to this election's equation.

Some Clinton backers find hope in early voting numbers along the border, although the state's urban areas have seen similar or in some cases bigger numbers.

Records are being eclipsed statewide, said Secretary of State Phil Wilson. He predicts 3.3 million Texans, more than a half-million over the previous record, will ultimately vote in the Democratic primary.

Early voting along the border is also surging — in El Paso County, more than three times the rate of four years ago, said El Paso Elections Administrator Javier Chacon — and both campaigns have made multiple swings through the area. A major part of Clinton's Texas initiative has focused on getting out the early vote, which in some areas accounts for about half of the total.

But mathematics and past voting trends may work against Clinton.

A blended system

A 1970s Democratic Party apportionment rule, ironically aimed at increasing women's participation in the process of selecting delegates to the national convention, is being increasingly viewed as a big plus for Obama.

Texans will participate in a blended system that includes both an election and a caucus as they pick their delegates to the August national convention.

Hillary Clinton supporters (back left) show up as Barack Obama supporters enter the auditorium for a performance by comedian George Lopez at the University of Texas at El Paso last week. Lopez endorsed Obama during the performance.

After polls close Tuesday, the precinct caucuses begin. There, 67 delegates will be selected based on the candidate they voted for. Some experts believe that will favor Obama, whose community-organizing model has helped him win 12 of the 15 states that have held caucuses.

"In El Paso, as well as around the state, Clinton needs to win the popular vote and then battle for the delegates at the precinct conventions," said El Paso state Sen. Eliot Shapleigh, a Clinton supporter. "But because of (Obama's) community organizing background, the delegate apportionment process probably will favor him at the precinct conventions."

A strong turnout by African American voters and a relatively low Hispanic turnout in the two prior elections are also working against Clinton's effort to end Obama's streak.

That's because past voter turnout determines how many delegates each of the 31 state Senate districts receive. The 126 delegates up for grabs in primary voting will be allocated to candidates based on their district by district vote totals.

The number of delegates up for grabs in each Senate district ranges from two to eight, and is based on the vote totals in the 2004 and 2006 races, said longtime party strategist Ed Martin.

Senate districts with heavy turnouts in those two elections will reap the reward Tuesday by having a greater proportion of delegates.

For example, three delegates will come out of Shapleigh's District 29, while seven delegates will come from Sen. Rodney Ellis' District 13 in Houston. Shapleigh's district is overwhelmingly Hispanic; Ellis' is overwhelmingly African American.

Obama is expected to benefit because, historically, African American voters in Texas have turned out in greater numbers and voted with greater frequency than Hispanics. It also may work to his advantage that there was not a significant effort by Democrats at the top of the ticket to get Hispanic voters to the polls in '04 and '06.

University of Texas-Brownsville government Professor Jose Bocanegra said Clinton has focused on heavily Hispanic regions, particularly in the Rio Grande Valley, where the former President Clinton is well regarded and where both Clintons have longstanding ties.

Bocanegra said Obama has put his effort in urban population centers with large black populations — Houston and Dallas-Fort Worth — and in rural areas of East Texas.

"He's basically trying to maximize his vote of supporters in those areas where African Americans tend to be more concentrated," he said.

Political scientists and party officials say women, who traditionally vote in greater proportion and more frequently then men, may also be a key for Clinton.

In fact, Clinton's gender may be a big selling point to Hispanic women.

Pharr Mayor Leo "Polo" Palacios, one of the Valley's political old-timers, recently drew hearty laughter at an event when he said in Spanish "Vóte por Mamá, no Obama."

So far, elderly Hispanic women are turning out in droves to vote early, said Diana Padilla, a voting judge at the Pavo Real Recreation Center, one of El Paso's busiest early voting sites.

"Clinton is drawing a lot of voters from the elderly ladies," Padilla said. "She is a woman, and Hispanic women are very impressed by her, and the fact that she, her husband and her daughter have all been visiting our city and talking to voters, that is a definite plus."

Maria Lerma, 52, was convinced even before she attended a recent Clinton rally.

"I don't want to sound racist, but I can't vote for" Obama, Lerma said in Spanish as she emerged from the polling site. "Even if he looks and sounds sincere, he does not convince me."

An energized electorate

Elected officials say they haven't seen this kind of energized electorate since the late 1960s, when an unpopular war and a troubled economy cost the Democrats the White House.

Last week, Rosas took off from work to stand outside a midtown El Paso early voting site and wave a Hillary sign. She said the week without pay won't help a pocketbook already wrecked by skyrocketing health care costs.

But compared to tens of thousands of her fellow Texans, Rosas can be considered lucky — she is insured, even if she can barely afford it.

According to the Census Bureau, Texas leads the nation with the highest percentage of its population without health insurance. Rosas said she is certain Clinton's proposed universal health care plan will change that.

"I think Hillary has to take this country in a different direction," said Rosas. "I know that she can do something for people like me, because health insurance is eating up" her income as a consultant and curriculum writer for a truck driving school.

The Clintons and daughter Chelsea have all separately crammed El Paso and Rio Grande Valley stops into their schedules over the past several weeks.

But some say it may not be enough.

"She is on the ropes nationally, so she has to cut into his traditional base of support," among African Americans around the state, said Rocha of UTEP. "His campaign appears to be out-mobilizing hers and he is getting traction from Hispanics, at least from Hispanic young people."

Throughout the region, the race has divided along generational as well as ethnic lines.

In some instances, the political divide extends to families, like the Lucios from Brownsville. Veteran state Sen. Eddie Lucio Jr. is backing Clinton, while his son, first-term state Rep. Eddie Lucio III is backing Obama.

In El Paso, County Attorney Jose Rodriguez, an avid Clinton supporter, was shocked last week when he saw his 5-year-old grandson sporting an Obama T-shirt.

"What's all that about?" Rodriguez asked.

"My jaw dropped when he looked his abuelita (grandmother) and I straight in the eye and said: 'Because Obama is winning and I want to be on the winning team,'" Rodriguez said.

"It left me with a very sinking feeling that all may be lost when I wasn't able to deter him, even after offering him some pizza to try and change his mind," Rodriguez recalled with a laugh.

"But there is one redeeming point to this for me," Rodriguez noted. "We are going to go vote for Hillary, and he can't vote."