More than 100 protesters blocked the main road leading to Trump's rally in this Phoenix suburb, chanting that he was a racist.
"Get this clown out of my town!" they shouted, carrying signs that read, among other things, "Trump = Hitler" and "Combat white supremacy."
Three people were arrested for blocking the roadway. Some of Trump's supporters, including retirees, had to walk three miles in the hot Sonoran Desert sun to his rally at a lakeside park.
At a rally later in Tucson, Trump criticized protesters who were trying to block supporters from getting into that event too.
"They're taking away our 1st Amendment rights," Trump said. "They're troublemakers. They're no good."
The New York billionaire looked across the crowd and said one troublemaker was wearing "a Ku Klux Klan outfit." Trump called him "a disgusting guy."
"If they had a match, they'd burn the American flag," Trump said of the hecklers disrupting his remarks.
Introducing Trump at both rallies were two top advocates of Arizona’s stringent measures against illegal immigration: Maricopa County Sheriff
In Fountain Hills, Arpaio’s hometown, Trump blamed immigrants in the country illegally for “so many killings, so much crime.” He then went after rival presidential candidates
Cruz, a senator from Texas, "wasn't born in our country, folks," Trump told several thousand supporters spread across the grass. "He was born in Canada. He's weak on immigration. He's in favor of amnesty."
As for the Ohio governor, Trump said: "Kasich is a nice guy, but honestly very weak on illegal immigration. That's the end of him, certainly as far as Phoenix is concerned, and as far as Arizona is concerned."
In advance of Tuesday's primary, Trump is running a television ad on Arizona stations saying he will "stop illegal immigration" by building a wall on the U.S.-Mexico border and bar Muslims from entering the United States as a temporary step to prevent terrorism.
"We're going to have a big, beautiful wall that nobody's crossing," he yelled to the crowd in Fountain Hills. "And nobody's going underneath either, by the way, just in case you had any question. Don't worry about the tunnel stuff."
Protesters hollered from a grass slope outside the rally, "Trump is hate!" But uniformed deputies from Arpaio's office kept them so far away that they could barely be heard.
At the makeshift roadblock, protesters denounced the candidate as his supporters looked on.
"Trump is very misogynistic, racist, sexist and a fascist," said Jeanne Mayeux, a 52-year-old Fountain Hills resident who carried a sign that said, "Stand against racism."
Mayeux is a member of MoveOn, one of several liberal groups that organized the protest. "I believe he would be a real danger if he gets into office," she said.
Bill and Evelyn Hoffman, Republican retirees from Rio Verde, Ariz., were in the first car directly facing the protesters.
"This is a bunch of nuts, but that's all right; they have their rights," said Bill Hoffman, 80, sporting a black cap with Trump's "Make America great again" slogan. "I don't like his methods, but what he stands for, I believe in."
Evelyn Hoffman, 76, added, "He got the whole country interested in politics, and he's indebted to nobody."
At both rallies, Arpaio and Brewer praised Trump's call for the border wall. And in Tucson, Arpaio boasted of the arrests in Fountain Hills.
"We locked up some demonstrators," he said to a burst of cheers, "and threw them in jail."