Daniel González

USA TODAY Network

The USA TODAY Network is spending time in eight counties in eight states, exploring the key electoral themes that could decide this fall’s election. Each week from now until the election, we will feature a different one. The series has so far looked at Waukesha County in Wisconsin, Chester County in Pennsylvania, and Wayne County in Michigan. Today: Maricopa County​ in Arizona.

PHOENIX — Fred Oaxaca bounded into a room inside a Phoenix union hall and yelled a cheer.

Se puede? (Can it be done?)

The room full of workers, mostly young Latinos in high school or their early 20s, yelled back even louder.

Si, se puede! (Yes, it can be!)

Oaxaca, a 21-year-old team leader for Central Arizonans for a Sustainable Economy, pounded the table with his palms, ending the cheer with a loud clap. The room shook as everyone joined in. They were pumped and ready to spend another afternoon going door-to-door in the 100-degree Phoenix heat, standing in shopping mall parking lots or riding the light rail to register new Latino voters.

“It’s all about turnout. Everything comes down to turnout,” Oaxaca said.

Still, turning that energy into votes here in Maricopa County won't be easy. No other demographic group represents so much potential and so much disappointment on Election Day.

The number of Latino voters has steadily increased nationally from one presidential election to the next: 11.1 million Latinos voted in 2012, up from 9.7 million in 2008, according to census data. But their voting rates lag significantly behind other demographic groups. In 2012, 48% of Latinos voted, compared with 66.6% of blacks and 64.1% of non-Hispanic whites, according to the Pew Research Center.

Republican presidential nominee Donald Trump's tough stance on immigration, anchored by a promise to build a giant wall on the southern border and make Mexico pay for it, may spur Latinos to the polls.

But Hillary Clinton, the Democratic nominee, has not yet ignited the same level of excitement nationally among Latino voters as President Obama did in 2012. He won 71% to 27% among Latino voters over Republican nominee Mitt Romney, according to Pew.

An Aug. 19-30 poll by the polling firm Latino Decisions showed 75% of Latinos view Obama favorably, compared with 68% for Clinton and 21% for Trump.

Perhaps no place illustrates the lackluster voter turnout among Latinos better than Maricopa County.

With more than 9,000 square miles, the county is larger than seven states. It is a sprawling mix of sun-drenched farming communities, tourist resorts, endless strip malls, red-tiled suburban housing subdivisions and the gleaming glass-and-steel office towers of Phoenix, the nation's sixth-largest city.

Six out of 10 Arizonans live in Maricopa County, which has 4 million residents. Its Latino population has soared in recent years, from 345,000 in 1990 to more than 1.2 million in 2014, and is now the fifth largest of any county in the nation.

The growth is driven in large part by a surge in voting-age Latinos who have turned 18 since the last presidential election.

Every month, on average, 2,042 Latinos in Maricopa County turn 18, compared with 1,975 whites — a trend also taking place nationally, according to estimates by the Morrison Institute Latino Public Policy Center at Arizona State University.

But when it comes to voting, Latinos here have a reputation of "punching below their weight."

Despite making up 30% of the population of Maricopa County, Latinos represented 14.7% of all votes cast in the county in 2012, according to data shared from TargetSmart, a consulting firm.

Overall, 76% of all registered voters in Maricopa County cast ballots in 2012.

Considering the size of the Latino population, their voting rates have been “surprising slow and evolving,” said Lattie Coor, the former president of Arizona State University who now runs the Center for the Future of Arizona, a think tank in Phoenix.

Many Latinos in Maricopa County don’t vote because they are legal immigrants who haven’t become naturalized citizens or they are in the country illegally and have no way to legalize their status and become citizens.

What’s more, data show people with high school diplomas and college degrees vote more often than those who don’t, Coor said. Latinos in Arizona are less likely to have high school diplomas or college degrees than other demographic groups, he said.

After leading the cheer, Oaxaca drove off to pick up a group of high-school students to take them to a neighborhood on the city's northwest side for an afternoon of voter canvassing.

Along the way, he passed strip malls of carnicerias and barber shops with signs written in Spanish and English. It's where Oaxaca grew up.

On this late afternoon in early September, Oaxaca was spending one of his last days working as a paid canvasser for the group known as CASE. He soon had to leave for the San Francisco Bay Area to start his senior year at Santa Clara University.

Since the beginning of July, Oaxaca had spent every afternoon registering new voters. By the time he left for college, his records show, he had registered 414 people, many of them young Latinos like himself with parents who are immigrants and can’t vote.

“There are a lot of other members of the community that have very similar (backgrounds) and if we aren’t voting, then we are voting against our own family,” he said. “Not voting only allows the status quo to continue.”

CASE is one of a dozen groups in Maricopa County that belong to One Arizona, a coalition of 14 nonprofit nonpartisan mostly immigrant and Latino rights groups that statewide is trying to register 120,000 new Latino voters after meeting its original goal of 75,000.

The group receives funding from the Unite Here labor union, among other progressive organizations. But because CASE is nonpartisan, canvassers can’t talk about particular candidates or take sides on political issues when registering voters, said Brendan Walsh, the executive director.

Its main focus is to get more Latinos to vote so both parties will pay attention to them, he said.

“Arizona’s politics and voting are largely dominated by an older group of white voters," Walsh said. "Younger voters and immigrant voters do not have a voice in Arizona, so we are trying to lift up that voice to make sure that our politics in Arizona is more representative of our population.”

After dropping the students off in a neighborhood, Oaxaca parked in a shopping complex parking lot. Clipboard in hand, he spent the next three hours walking up to strangers to ask, "Excuse me, are you registered to vote?" And if not, "Can I ask why?"

His goal was to register eight new voters that evening or convince as many existing voters to sign up for mail-in ballots. Registered voters who receive mail-in ballots are far more likely to actually cast ballots than those who have to drive to the polls on Election Day, Oaxaca said.

The work was slow going.

Most people ignored Oaxaca and kept walking. Some told him in Spanish they weren’t eligible because they aren’t citizens. Others said they didn't have time or didn't think their vote mattered.

An hour passed before Oaxaca logged his first mail-in ballot registration.

Lisa Perez, 31, said she registered to vote for the first time in July because she wanted to vote against Trump, whose rhetoric she found offensive to Latinos.

"I thought, my vote is going to count this year because I definitely do not want him to be the president," said Perez, a credit-card financial-services auditor.

The push to register Latino voters in Maricopa County mirrors drives taking place in counties around the country with significant and fast-growing Latino populations. Among them: Clark County, Nev.; Marion County, Ore.; Adams County, Colo.; Kane County, Ill; Hampden County, Mass.; Prince William County, Va.

In Maricopa County, efforts have focused heavily on the disproportionately high number of Latinos who are eligible to vote but aren't registered, said Ian Danley, director of One Arizona.

Based on data from TargetSmart, shared by One Arizona, 224,129 Latinos in Maricopa County are eligible to vote but are not registered, while another 352,553 are registered. That means about 61% of the 576,682 eligible Latino voters in Maricopa County are registered, compared with 74% of the eligible non-Hispanic whites, according to the TargetSmart data.

A concerted effort also is under way to register Latinos who reached voting age since the last presidential election. Approximately 96,000 Latinos in Maricopa County have turned 18 since November 2012, according to Dan Hunting, senior policy analyst at ASU’s Morrison Institute, based on census data he analyzed from the American Community Survey.

Esther Rivera turns 18 on Oct. 23, 16 days before the presidential election. She registered in July, hoping her vote will help bring immigration changes that will benefit her mother and 21-year-old brother, who are both undocumented. Her brother received a deportation deferment and temporary work permit under Obama’s 2012 Deferred Action for Childhood Arrivals program.

“The main reason I want to vote this year is to put my voice out there for the voiceless,” Rivera said. “My mother, she cannot vote, but I can and there (are) a lot of people out there in my community who can’t vote, but they want to. … Just one vote can help a lot, as long as we try.”

Irma Maldonado, an 18-year-old nursing student at Grand Canyon University, will also be voting for the first time.

Maldonado was forced to move to San Felipe, a small town in the coastal state of Nayarit in Mexico, in October 2012 after her mother, who had lived in the U.S. without documents for 20 years, could find no way to legalize her status and decided to “self-deport.”

Maldonado, a U.S.-born citizen, returned in 2014 to live with her sister in Phoenix and finish high school. She plans to use her vote to “say no to Donald Trump.” Still, she’s not sure she’ll cast a ballot for Clinton.

“I think it would be awesome if we had the first woman president,” she said. But she isn’t sure she can trust Clinton after Obama made similar promises to pass immigration reforms but failed to deliver.

“She is saying the right thing, but she isn’t going to do anything about it,” said Maldonado, who favored Vermont Sen. Bernie Sanders in the Democratic primary.

At the same time, many Latino Republicans are finding it hard to vote for Trump.

Felix Garcia, 34, an immigrant from Hermosillo, a city in the northern state of Sonora across the border from Arizona in Mexico, is a naturalized U.S. citizen who owns a construction company in Phoenix.

Originally, he supported former Florida governor Jeb Bush because of his stance on immigration.

But he’s now campaigning to get Latinos to vote for Libertarian Gary Johnson, who like Clinton supports immigration reforms that would provide a pathway to citizenship for undocumented immigrants.

“Donald Trump, I don’t like his attitude with the Hispanic community. He is very aggressive,” Garcia said.

Some believe strong turnout by Latino voters could help tilt Maricopa County in favor of Clinton, which would all but guarantee a win for the Democratic nominee in Arizona.

That may seem far-fetched, considering Maricopa County's long track record of voting GOP in presidential elections. The county has swung Republican in every presidential election since 1948. Even Bill Clinton, the last Democratic presidential candidate to win Arizona in 1996, lost Maricopa County to Republican nominee Bob Dole.

Romney carried Maricopa County over Obama in 2012 by nearly 11 percentage points, 54.3% to 43.6%.

But a statewide Arizona Republic/Morrison/Cronkite News poll showed the race in Maricopa County between Clinton and Trump too close to call. The poll, conducted Aug. 17-31, found Clinton leading Trump 34.2% to 33.2% among likely voters, well within the poll’s margin of error.

In such a tight race, Latino voter turnout could make the difference. The same poll showed Clinton leading Trump among Latino voters by a wide margin, 45.3% to 14.6%. Another 29.8% hadn’t decided.

If Clinton wins Arizona this fall, it will be due to the large number of Latino voters in the state and in Maricopa County who vote Democratic, said Joseph Garcia, director of the Morrison Institute’s Latino Public Policy Center at ASU.

In Maricopa County, nearly 43% of Latino voters are registered Democrats, 16.2% are registered Republicans and 41% are registered as independents or other party, according to TargetSmart estimates.

"If they do so," Garcia added, "I think it will be in large part in repudiation to the top of the ticket, and that’s Donald Trump, who continues to talk about building a wall, deporting them all and has never ever apologized for referring to Mexicans as criminals and rapists.”

The Latino youth vote also will be a critical factor.

The county’s Latino population is significantly younger than the rest of the population: The median age for Latinos is 25, compared with 43 for whites.

“Latinos are largely young, still too many Latinos don’t graduate from high school, much less college, and as a result Latinos disproportionately live in poverty, so what you are talking about are three very tough groups to get out to vote,” Garcia said.

Oaxaca, the son of immigrants, plans to become the first person in his family to vote for president of the United States. And when he does, he hopes he will be joined by the hundreds of other Latino voters he’s registered in Maricopa County.

"The reason why it’s exciting for me, is the other work that came before it,” he said. “For me, that is what is exciting.”

To report this series, the USA TODAY Network identified eight counties around the country that represent key voting groups in the November election, from blue-collar and college-educated voters to rural voters and Latinos. Journalists spent time with voters, political observers and experts in these eight counties — blue, red and purple — talking about the presidential candidates, the issues and the importance of this year’s election.

• Week 1:GOP “base” voters in Waukesha County, Wis.

• Week 2:White, college-educated voters in Chester County, Pa.

• Week 3:African-American voters in Wayne County, Mich.

• Week 4: Latino voters in Maricopa County, Ariz.

In the coming weeks, look for our coverage of the following counties: Union County, Iowa; Larimer County, Colo.; Clark County, Ohio; and Hillsborough County, Fla.

The Deciders: A look at 8 key counties that are going to help decide this election

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