FOUNTAIN HILLS, Ariz. — David Rau wasn't sure about Donald Trump. So the landscape contractor strolled over to the main park in this Phoenix suburb to watch one of the businessman's recent rallies and decide for himself.
Demonstrators pulled their cars across an access road to block people driving to the event. Dozens marched to the park and stood by Rau, chanting "Stop the hate!" as he tried to listen. He left a Trump convert. "I've got the right to listen to somebody speak, don't I?" Rau asked.
Trump's rise in the Republican presidential contest has sparked increasingly confrontational protests, mobilized his opponents and drawn scrutiny of the GOP front-runner's rhetoric and the sometimes rough way his campaign handles dissent. But as demonstrators escalate their tactics, they also risk helping Trump, especially among Republican voters his rivals are furiously trying to persuade to reject the billionaire businessman.
"I encourage people to speak out against Trump in a forceful but respectful manner because some of these protests are only serving to help him," said Tim Miller, a spokesman for a Republican group trying to stop Trump. "He continues to dominate the news, he can play the 'us vs. them' card when liberals disrupt his events and that serves as a rallying point for his candidacy."
Even Vermont Sen. Bernie Sanders, running for the Democratic presidential nomination, has been troubled by protesters' tactics, as well as by Trump's response.
"In America, people have a right to hold rallies," Sanders told MSNBC. "It is absolutely appropriate for thousands of people to protest at a Trump rally, but I am not a great fan of disrupting rallies."
Trump engages the demonstrators vigorously, mocking them, calling them bad people and sometimes feeding the anger of his supporters in the crowd.
The Phoenix demonstration followed one in Chicago, where hundreds of Trump foes flooded into a rally and Trump canceled the event, citing security concerns. That infuriated Trump backers, who blamed the demonstrators.
In Arizona, activists gathered about 3 miles from the site of the Trump rally, along one of two roads that wind through the mountains north of Phoenix into central Fountain Hills. The protesters — mainly a coalition of local immigrant rights groups who have a long history of demonstrations against Sheriff Joe Arpaio, who was speaking at the rally — then maneuvered their cars across the intersection. Three were arrested, and many Trump supporters had to walk to the rally or missed it.
Carlos Garcia of Puente, one of the immigrant right groups, said demonstrators handed out water bottles to Trump supporters and did not want to antagonize them.
"I hope people see beyond their two-hour inconvenience," he said, adding that activists were motivated by the support Trump has drawn from Arpaio and former Arizona Gov. Jan Brewer. "Their rhetoric," he said of that duo, "turned into policies that destroyed thousands of families, and we see Trump trying to go national with it. People are willing to put their bodies on the line to keep their families together."
When Garcia and other demonstrators made it to the park where Trump was holding his rally they were met with jeers and cries from Trump supporters gathered on the hillside, outside the fenced-off perimeter where the event was occurring. "Learn to speak English!" one person yelled at the protesters. "Gotta get off the welfare check," called another.
The demonstrators chanted back: "Stop the hate!" Despite some heated scrums, no fights broke out and eventually the candidate finished and protesters and supporters alike trickled away.
Sharon Groves, a 69-year-old retired social worker, came to the rally with a group of Fountain Hills' few other liberals. The crowd spilled out from the controlled area onto a hillside where Groves stood silently wearing a shirt that read "Prays well with others" and included symbols of world religions. Some other demonstrators silently held up homemade signs that read: "Love Trumps Hate."
Afterward, Groves was horrified at the demonstrators who blocked traffic and then marched in. "It was uncalled for," Groves said. "People have the right to come and see him if they want to."
This story has been corrected to reflect that an Ohio event was not canceled.
Associated Press writers Jacques Billeaud in Fountain Hills and Daniel Sewell in Dayton, Ohio, contributed to this report.
Follow Nicholas Riccardi on Twitter at https://twitter.com/NickRiccardi.