Colorado, Nevada and New Mexico are independent-minded states that once leaned Republican but are trending Democratic, partly because of increasing numbers of Hispanic voters alienated from the GOP by its tough stance on illegal immigration.

California, a GOP bastion for decades, is now solidly Democratic and the ultimate example of the dangers for Republicans on this issue.

Nowhere is a harder line on immigration taken than in Arizona, where Republicans have a lock on statewide offices and dominate the Legislature.

In November, Democrats picked up a congressional seat, but Republican presidential nominee Mitt Romney easily won the state with a slightly better margin against President Barack Obama than Arizona Sen. John McCain posted in the 2008 White House contest.

That record has led advocates of tighter immigration restrictions to point to Arizona as a model for how Republicans can maintain their tough stance on the issue and still win elections.

“It’s an example of a different way for things to play out than the conventional story,” Mark Krikorian of the Center for Immigration Studies, a Washington think tank that favors tighter immigration policies, said of Arizona. “What’s happened there is the non-Hispanic vote has become increasingly Republican.”

National Republicans, aware of demographic trends, are pondering how to win over more Hispanic voters in order to be more competitive in presidential elections. It’s unclear whether Arizona will remain a GOP stronghold.

Plenty of Arizona Republicans fear their state will go the way of its neighbors unless the GOP softens its immigration stance. That includes McCain, who in 2005 joined with Sen. Edward Kennedy, D-Mass., to sponsor legislation that included a pathway to citizenship for immigrants in the country illegally.

A staunch supporter of strict border enforcement in 2008 and 2010, McCain has swung back after last year’s election to supporting an overhaul of the immigration system that includes citizenship for those in the U.S. without authorization. He says he was convinced the GOP could not survive with a hard-line stance in states like his.

“If you have a large bloc of Americans who believe you’re trying to keep their … fellow Hispanics down and deprive them of an opportunity, obviously that’s going to have an effect,” McCain told reporters earlier this year.

During the 2012 presidential campaign, Romney called for “self-deportation,” or creating an environment so uncomfortable for immigrants here illegally that they would choose to return to their original countries. Romney also praised Arizona’s approach to immigration.

Two years earlier, the state became well-known for restrictive immigration legislation with the passage of legislation requiring police officers, while enforcing other laws, to question the immigration status of those they suspect are in the country illegally. While that part of the statute survived, the U.S. Supreme Court struck down three other provisions of the law.

Arizona’s stance has national implications as leading Republicans try to reorient their party following the 2012 election, when Hispanics, African-Americans and Asians went for Obama in overwhelming numbers.

A Republican National Committee panel recently released a report that advises more outreach to minorities and support for an immigration overhaul that eventually would legalize the status of most immigrants who are in the U.S. illegally. That’s an idea that’s anathema to some Arizona Republicans.

A bipartisan group of eight senators, including McCain and Jeff Flake, R-Ariz. ai??i?? is drawing up a bill that includes such a provision.

Arizona was always one of the less-promising states for Democrats for reasons other than immigration, said Scott Smith, the Republican mayor of Mesa, a Phoenix suburb.

“You have a lot of retirees in Arizona ai??i?? Midwestern, conservative Republicans,” he said. “Republicans far outnumber Democrats in registration, and the independents tend to be conservative more than liberal.”

President Bill Clinton helped make immigration a major issue in Arizona.

In an attempt to tamp down illegal immigration in California, his administration fortified the border with Mexico in the late 1990s.

The bolstered enforcement effectively pushed migrants east into the mostly empty desert that straddles Arizona and the Mexican state of Sonora.

As crossing into the U.S. became harder, drug cartels and criminal syndicates expanded into human trafficking, with Phoenix becoming a major hub. The federal government warned Arizonans to stay out of various parks and swaths of public land for fear they could stumble across armed smugglers. There was widespread fear.

“That entire impact just changed the way undocumented immigrants were seen in Arizona,” said Alfredo Gutierrez, a former Democratic president of the state Senate and an immigrant rights activist. “It raised all kinds of opportunities for people to exploit this.”

Since the passage of SB 1070, the battles over immigration have torn the state’s Republican Party.

Business leaders successfully stopped the passage of more aggressive measures in 2011. The law’s architect, former State Senate President Russell Pearce, was recalled from office and last year lost a Republican primary trying to return to office.

“Republicans in Arizona have shifted pretty dramatically in how they look at this issue,” said Glenn Hamer, president of the Arizona Chamber of Commerce, which spearheaded the push to block more stringent immigration legislation and supports the federal immigration overhaul.

“If the current voting patterns hold, it’s impossible to see in 10-20 years the same sort of results for Republicans” as they enjoy here now, he said.

From Hamer’s perspective, the math is basic.

Arizona has stayed Republican because in exit polls over the past decade whites, currently 74 percent of the state’s voters, have backed GOP presidential candidates by roughly 3-to-2 margins, even while Hispanics vote Democratic by 3-to-1. By contrast, whites only narrowly supported Republican presidential candidates in neighboring swing states.

Hispanics are 30 percent of Arizona’s population but made up only 18 percent of its voters in November. One-third of them are not citizens and cannot vote, while 18 percent of the Hispanics are here illegally.

But Arizona’s Hispanic population is unusually young, with a median age of 24, while its white population is significantly older, with a median age of 44. Political analysts say that makes it inevitable that at some point in the next decade or two Hispanic voters will overwhelm white voters.

Nonetheless, plenty of Arizona politicians are holding their strict stance in the immigration debate.

Recently, Attorney General Tom Horne, who came to prominence by banning a Mexican-American studies class in Tucson schools, argued for the constitutionality of a 2005 referendum that requires all voters to prove citizenship before casting a ballot.

The Legislature is considering tightening voting procedures in a way that Latino activists contend will lead to a disproportionate number of their voters being dropped from the rolls.

Gov. Jan Brewer became a heroine to those who favor immigration restrictions after signing SB1070. She has lashed out at the suggestion by the Obama administration and immigrant rights groups that the border is secure enough to legalize the status of many immigrants.

“A lot of the legislation we passed is in concert with what the people demanded of us,” said state Rep. Steve Smith, a Republican who is author of a bill allowing the state to collect donations to build a border fence.

“We have a front row seat to it. People see the direct, detrimental effect of the drugs, the gangs, the smuggling and what they are doing to our state.”

Smith said he thinks Republicans should not abandon their forthright stance on immigration because it has won them support in Arizona and beyond. “Don’t sell your morals, beliefs and thoughts down the river,” he said. “When I, or other elected officials, or our governor, go to other states, people there say ‘Thank God for Arizona.'”