In black T-shirts with  "Support the DREAM Act" emblazoned on the front, undocumented Latino young people  walked the streets of Arizona in recent days, drumming up support for their fight against the Republican presidential hopefuls' stances on immigration. One youngster said he met people who expressed  "disappointment in what the Republicans are today." Another said he heard "anger" at the candidates "attacking the Latino community."

The young people's destination? The state's GOP headquarters, where they would drop off a petition with 8,000 signatures from Arizonans upset about the party's rhetoric on the controversial issue. Their goal? Let Republicans know - only a day before Tuesday's state primary - that what the candidates' say about immigration comes with consequences .

In a border state where 18 percent of the eligible voters are Latino, where sensitivity runs high a year after the state enacted a strict immigration law, every comment from the potential next occupant of the White House carries a little more weight. Arizona front-runner Mitt Romney lauded the state's new law as "a model" for the nation  last week, while rival Newt Gingrich called suggestions that the U.S. could not secure the southern border "utterly stupid."

Such remarks should come as no surprise in a primary that has seen the Republican candidates veer further and further to the right . Only weeks ago, Romney touted the endorsement of Kris Kobach, the author of the immigration law. Every candidate, including Romney, has voiced opposition to the Dream Act, the Democrats' bill to provide a path to citizenship for some children of undocumented immigrants who attend college or serve in the military. After last week's debate in Mesa, Democratic National Committee chairwoman  Debbie Wasserman Schultz argued that the Republicans had "spouted more extreme anti-immigrant rhetoric" because they are "tripping over one another to appeal to the far right -wing extreme of their party."

Even with the state's sizable Latino population, Republicans have little need to worry about alienating Latinos before Tuesday's primary. Hispanics in Arizona tend to back Democrats, as evidenced in 2008 when only 7 percent of GOP primary voters were Latino. In addition, Romney appears to have opened up far too large a lead in the state for the opposition of any Latino Republicans to make much of a difference in the voting there. According to an NBC/Marist poll last week, Romney leads his closest rival Rick Santorum 43 percent to 27 percent.

But if he secures his party's nomination , Romney could have real cause for concern about his chances in Arizona come next fall's general election showdown against President  Obama. Latinos are the nation's fastest-growing voting bloc - an estimated 12.2 million will vote this year - and they have the potential to be a decisive force in November, especially in Arizona.

Two years ago in Arizona's governor's election, largely viewed as a referendum on incumbent Gov. Jan Brewer's immigration law, 71 percent of Latinos supported her Democratic rival, Terry Goddard. While Brewer ultimately emerged victorious, Obama's team will be encouraged by their chances of winning Arizona in the fall.

Despite having  won the state only once since 1952 - Bill Clinton's 1996 victory - signs point to the Democrats standing a decent chance at springing another surprise this year. According to a recent poll conducted by Latino Decisions for ABC News and Univision, 72 percent of Latinos nationwide said Republicans either don't care too much about Latinos or are outright hostile toward Latinos: 45 percent in the former category and 27 percent in the latter. Only 17 percent of respondents said the GOP was doing a good job of reaching out to Latinos.

In addition, 41 percent of Latinos nationwide have a somewhat unfavorable or very unfavorable view of Romney. In a hypothetical general election matchup, 67 percent of Latinos said they would back Obama, compared with only 25 percent for Romney. And when it comes to the controversial Arizona immigration law, in particular, Latinos nationwide overwhelmingly oppose it regardless of where they live.

"Distance from the state and immigrant experience have no bearing," analyst Sylvia Manzano wrote on the Latino Decisions website this week. "U.S. and foreign-born Latino voters in Arizona are equally concerned about the potential impact on Latino Americans."

" Candidates, issues, and party strength  will vary across states and contests, but Latino voter distaste for rhetoric and policy detrimental to the group will remain constant," Manzano concluded. "We can count on that."

To that end, the Obama campaign is now trying to make a push for Arizona, despite only one win there in the past six decades. The campaign has already set up three field offices in Phoenix, Tucson and Flagstaff, and a fourth will open in Glendale in the coming weeks. The campaign has already held nearly 250 phone banks, 500 voter registration events, and dozens of Latino-focused events. Late last year, senior adviser David Axelrod was dispatched to the state to meet with volunteers, community leaders, campaign staff and local elected officials.

While home-stater Sen. John McCain cruised to a nine point victory against Obama in Arizona in 2008, this time around - with a nominee from out of state and a disillusioned Latino electorate - it might not be so easy for the GOP. Even one of the GOP's newest stars - Florida Sen. Marco Rubio - this month warned his fellow Republicans of the political dangers of their attitudes toward  immigration.

"I'm always trying to remind my colleagues that if they lived in Mexico or anywhere in Latin America and their kids were hungry - every night went to sleep hungry - and your country provided no opportunity for you to feed them, you're telling me that there's nothing you wouldn't do to feed them? You're telling me you wouldn't go anywhere there was a job so you could send money to them?" Rubio said in an interview with Time  magazine . "I think the vast majority of people who enter this country illegally and legally do so because they're looking for a better life, more opportunity for their kids. And I think we need to recognize that. I think we need to understand that many of them are doing what many of us would do if we were in the same position. That doesn't excuse it. That doesn't mean you legalize it. That doesn't mean you overlook it, but I do think it puts a human element to it."

"What's the Republican legal-immigration plan? And that's a problem, when all they hear from you is what you're against and not what you're for," he said. "The Republican Party has to become the pro-legal immigration party. It has to be a party that puts out two things: a commonsense, compassionate yet law-based response to people that are here without documents, and a robust legal-immigration system that emphasizes border security, worker security and a workable visa program. We have to have a proactive policy in that regard, and we haven't."

A possible Latino backlash this November has Democrats looking to pounce. They know the importance of a potential victory in a consistently Republican state like Arizona.

"Arizona's Latino community faces a key choice in this election," warned Rep. Xavier Becerra, D-Calif.. "The Republican field would be disastrous for the priorities of Latinos."

With Arizona seemingly in play for Democrats this fall, expect that to be a message that they hammer home time and time again in a bid to retain the White House. No matter who emerges from the Republican Party's unpredictable primary battle, the GOP, when it comes to Latinos, will clearly have some work to do.

Matthew Jaffe is covering the 2012 campaign for ABC News and Univision.