PHOENIX, AZ — Long before Donald Trump shook up presidential politics, there was Sheriff Joe Arpaio. Now the two are politically joined, and the Republican presidential front-runner can look to Arpaio’s home state for a model on how he could win in November.

The tough-talking lawman won six straight elections as sheriff of Maricopa County, which includes Phoenix and nearly two-thirds of Arizona’s population. He forced jail inmates to wear pink underwear and live outside in tents during triple-digit heat. He launched dragnets to round up people in the country illegally, and a judge ruled that his operations illegally targeted Latinos. Arpaio then launched an investigation that critics contend ended up targeting the judge.

Through it all, Arpaio won re-election even as the number of Latinos in Arizona continued to rise, and his endorsement was hotly sought by Republicans who have thrived in the state despite its increasing diversity. GOP presidential candidates have also wooed Arpaio, who’s become a national icon for opponents of illegal immigration. He endorsed Trump last year and introduced him at two Arizona rallies, and is scheduled to introduce Trump at a rally Saturday in the Phoenix suburb where the sheriff lives.

Now, as Trump looks toward the general election, Arpaio and Arizona — the next major state to vote in the presidential nominating contest — show how conservative populists can thrive even in states with growing minority populations. Arizona votes Tuesday in a winner-take-all Republican primary as well as a Democratic race.

“My secret weapon is just like Donald Trump: Go to the people,” Arpaio said in an interview. He said he’s done more than 4,000 TV interviews in his two decades as sheriff.

If Trump wins the Republican nomination, he will face a daunting challenge for the November election: Given that minority voters strongly lean Democratic, he would probably have to win more white voters than any other presidential candidate in the modern age has done — about two-thirds of them, should turnout and minority voting patterns track 2012 levels.

In Arizona, though, Republicans like Arpaio have prospered by winning an increasing share of the white vote even as the number of Latinos in the state has risen from one-quarter of the state’s population to 31 percent in 2014. A Democrat has not won a statewide election since 2004, and voters continue to register as Republicans faster than as Democrats or even independents.

Francisco Heredia of Mi Familia Vota, which tries to increase Latino voting, said the principal political struggle is between the growing population of young Latinos and people in Arizona’s retirement communities. Retirees are “squashing any kind of growth” for Latino political clout.

Whites as a share of the electorate have slipped from about 80 percent in 2000 to the high 60s, Heredia said. That’s not enough to swing statewide races, but it has made a difference on the margins. The city of Phoenix, for example, went from one Latino city council member in 2010 to three today.

The disparity between the performance of Arizona Republicans and Democrats stems from increased illegal crossings of the Arizona-Mexico border more than a decade ago. Republicans had a long tradition of moderation on immigration in Arizona. Both U.S. senators once supported an immigration bill that would have legalized the status of many of the 11 million people here illegally, but they took an increasingly hardline approach in the 2000s. Arpaio and Jan Brewer, then the governor and now another Trump endorser, represented this hard line as people grew more concerned about the drug smugglers and human traffickers flowing into the state.

“We had drop houses, we had running gun battles — it was the Wild West,” recalled Chuck Coughlin, a veteran Republican operative who was a Brewer adviser. “We all saw the handwriting on the wall on the immigration issue.”

The chaos on the southern border has dwindled significantly, and business groups have pushed for the state’s Republicans to tone down their immigration rhetoric. But Republicans still have a lock on statewide offices. Part of the reason is that Democratic-leaning voters, including the state’s many young Latinos, have sat out elections while Republicans have turned out reliably, said Bruce Merrill, a nonpartisan Arizona pollster.

“The Democratic Party in Arizona continues to be very disorganized,” Merrill said.

Arpaio won his last election, in 2012, by 6 percentage points, his second-smallest smallest margin to date. He faces civil contempt charges over his department’s defiance of orders to stop racial profiling. But Republicans still court his support and he remains very popular in conservative Maricopa County.

“We have a real populist tradition here,” said Coughlin, adding that he expects it will help Trump as it has Arpaio.

Hillary Clinton’s campaign has seized on the Trump-Arpaio parallel in a Spanish-language radio ad pitching Clinton as the best candidate to beat Trump. “Donald Trump is another Joe Arpaio. Period,” says Rep. Ruben Gallego in the spot.

Even Arpaio, 83, acknowledges the state is changing.

“It’s not as dominated by Republicans,” he said. “You’ve got a lot of people moving in, a lot of independents.”

Still, Arizona has favored Republicans in presidential elections since the early 1950s with one exception — a squeaker for Democrat Bill Clinton in 1996. And Merrill says, “I don’t see it changing anytime soon.”