Since then, Zacarias has become a U.S. citizen, been elected to his city council and gone door to door to persuade neighbors to vote for Obama, exemplifying the growing political influence of the Latino community in the state.
"The Latino vote could be a decisive factor in the next election, at least here in Iowa," said Zacarias, who moved to West Liberty in 1984 after leaving Mexico. "I see a lot of enthusiasm."
It's not just Iowa where Latino voters could make a difference. Virginia, North Carolina and Ohio are other presidential battlegrounds that don't have huge numbers of Hispanic voters — unlike Nevada, Colorado and Florida — but where polls show close races in which any factor could determine the outcome.
In Iowa, behind a population boom and an influx of newly enfranchised citizens, the number of Latino voters is expected to increase in November, bringing a new sense of importance and more campaign attention to a part of the electorate that has been little noticed in many states. Nobody knows how many more Latinos will vote in Iowa, but the League of Latino United Citizens, or LULAC, which is conducting a major registration drive, is aiming to boost Latino turnout in Iowa from the 35,000 in 2008 to 50,000 this time, or about 3 percent of the state's overall total.
Even such a modest share could be meaningful if the race in Iowa is close, as recent polls suggest it could be, and if the Democratic president carries the two out of three Latino votes that he did in 2008. Republicans working for Mitt Romney's campaign are trying to reduce Obama's advantage, as both parties woo Latinos in a place typically portrayed as an all-white farming state and that is now one of the key Midwestern battlegrounds that will determine the election's outcome.
Iowa's Latino population, though far smaller than the Sunbelt states, increased 84 percent from 2000 to 2010 to more than 151,000. That's about 5 percent of the state's overall total. It's a similar story in other key toss-up states, with the Hispanic population rising to about 8 percent in North Carolina and Virginia. Ohio's Latino population is 3.1 percent but has grown by 63 percent since 2000.
The full influence of the larger Latino population still won't be felt. Less than half of those in Iowa will be registered to vote this fall, since many are too young or not U.S. citizens. Hispanic voter turnout is traditionally low. But those who are eligible say immigration policies from both parties that they consider to be harsh and fallout from the recession may help drive turnout.
West Liberty, a town of 3,800 between Davenport and Iowa City in the cornfields of eastern Iowa, became the first in the state where Latinos are the majority, according to 2010 Census data. For years, residents have come from Mexico and Central America to find grueling work at a huge turkey processing plant now called West Liberty Foods. The city's schools are known for their bilingual education.
Residents interviewed downtown, where the insurance agency and bar advertise in both English and Spanish, say they feel betrayed because Obama didn't deliver on campaign promises to overhaul the nation's immigration system. Many praised Obama's executive order halting deportation proceedings for illegal immigrants who were brought to the U.S. as children, but others see it as a political move that could be undone.
Nereida Velez, 23, said she would vote for Obama if she could. Born in Mexico, she moved to Arizona as a child and her family later settled in West Liberty to find work: her father as a painter, her mother at the turkey plant. She is applying for Obama's program to defer the possibility of deportation while she works to become a resident.
"Since we are Latinos, he offers more opportunities for us," said Velez, a stay-at-home mother of a 2-year-old girl who was getting her hair done in downtown West Liberty. "I like him."
Turkey plant worker Erika Reyes, 19, said she hasn't made up her mind. She's upset with Obama, but knows little about Romney.
"Obama has been saying what he wants to do, but he didn't do it once he was elected," said Reyes, sitting on a downtown bench with her 7-month-old daughter. "People actually believed in him, and I don't know what to think now."
Obama easily carried Iowa in 2008, but the state voted heavily Republican in midterm elections two years later. Republican George W. Bush barely won the state in 2004, after Democrat Al Gore narrowly defeated him in 2000.
Obama volunteers cite the president's program to help young illegal immigrants, the health care reform law and increases in college aid as good for Latinos. Republicans argue that Romney can boost the economy, noting high unemployment rates among Latinos, and appeal to Latinos on conservative social issues such as abortion.
"Both parties understand the numbers," said Mark LeRette, the GOP chairman in Muscatine County, which has one of the state's largest Latino populations. "This could be a close election, and that's going to be a cross-section that could help decide it."
LeRette, who hands out bilingual campaign literature at the county fair and summer parades, calls Latinos "a naturally conservative community." He hopes Republicans are doing enough to court Latino voters.
For many Latinos, the choice will be between a president they feel has ignored them and a challenger who could be worse, said Ila Plasencia, 85, of West Des Moines.
"I'm not happy with either one, but if Mitt Romney gets in, I think it's going to be hell for the Latinos. He wants to do a lot of things that is contrary to what we want," said Plasencia, an influential community activist who runs a nonprofit that helps new citizens and promotes education.
Obama is trying to patch up hard feelings. In a three-day trip to Iowa in August, he had a campaign rally in Marshalltown, a city of 28,000 with a sizable Latino population. His campaign created a council of 26 Latino leaders to mobilize voters.
LULAC, a nonpartisan group, is contacting Hispanic voters and asking them to help find family members to register. Organizers will set up booths at upcoming Latino festivals in Cedar Rapids, Davenport and Fort Madison. The goal of signing up another 15,000 Latino voters should be achievable, said LULAC state director Joe Henry.
"When it comes to the Latino community in Iowa, neither political party has ever done an aggressive campaign like this," he said. "It's significant for us, and I think it's significant for the election."