SAN JOSE, Calif. — Outside Donald Trump’s campaign rallies in recent days, protesters have gathered and, increasingly, clashed violently with Trump supporters and police. Inside, Trump is going to new rhetorical extremes in his attempts to delegitimize a Mexican-American judge. Together, they’re forming an increasingly combustible atmosphere as the campaign enters the summer and temperatures here climb into triple digits.

Trump has in the past vowed to become more “presidential” after dispatching his primary foes, and many political observers hoped tensions would decrease as Trump pivoted to appeal to a broader swath of voters in the general election.


Instead, the end of the primary has seen a steady rise in tension, fueling fears that the convention in Cleveland next month will surpass the turbulence of the 1968 Democratic convention in Chicago.

Tense standoffs involving police, protesters and Trump supporters are common sights at campaign rallies, and violence has occasionally flared up, but there has been an uptick in the scale and frequency of violence over the past two weeks during the candidate’s swing through the West. Most of the violence has been directed at police officers and Trump supporters outside rally venues, but on Friday, one local leader who condemned the violence also partly blamed Trump for it.

“While it’s a sad statement about our political discourse that Mr. Trump has focused on stirring antagonism instead of offering real solutions to our nation’s challenges, there is absolutely no place for violence against people who are simply exercising their rights to participate in the political process,” said San Jose Mayor Sam Liccardo, a Democrat, in a statement on Friday. In another statement, Liccardo said Trump’s rhetoric is no excuse for violence and that city police would investigate and prosecute offenders.

A spokeswoman for the Trump campaign, Hope Hicks, did not respond to a request for comment.

Demonstrators threw eggs at Trump supporters and orange traffic cones at police officers on Thursday. San Jose police have already made four arrests — including for assault with a deadly weapon — and one officer suffered a minor injury after being struck by a metal object, according to a statement from the city’s police department.

Thursday night’s violence came on the heels of similar disturbances at Trump rallies in San Diego and Anaheim, California, and Albuquerque, New Mexico, as arrest numbers mount. While tensions often run high outside Trump rallies and violence occasionally erupts, Trump’s campaign swing out West over the past two weeks has been an unusually cantankerous stretch.

It kicks off what could be a long, hot summer with medical staffers patrolling recent rallies in California this week on the lookout for fainting and dehydration victims. This Friday’s rally in Redding was held outside on pavement in 100-degree heat.

Outside a campaign rally in San Diego on May 27, police aggressively dispersed a crowd of 1,000 rowdy protesters and Trump supporters, making roughly three dozen arrests.

In Anaheim, where some demonstrators threw small stones at cars in a parking garage at the site of a rally on May 26, there were 22 arrests around the event, 19 of them for vandalism and failing to disperse, according to Anaheim police detective Laura Lomeli. She said no protesters had applied for permits to demonstrate. In Albuquerque, where demonstrators shattered windows at the site of Trump’s rally on Tuesday, police made three arrests and have an outstanding felony warrant for another demonstrator that includes eight counts of aggravated battery on a police officer, according to Albuquerque Police public information officer Tanner Tixier. He added that police were working four to five other cases that could lead to more arrests.

Tixier also shot down as “conspiracy theories” rumors that anti-Trump demonstrators were illegal immigrants or paid agitators.

“They’re just general local criminals. I don’t even think they knew what they were protesting,” he said.

The Mexican flag has been a common sight at recent protests in the West, which is home to many Mexicans and Mexican-Americans. Trump, meanwhile, began insisting during the past week that the judge presiding over one of the lawsuits against Trump University, Gonzalo Curiel, could not be fair because of his Mexican heritage. The statement — condemned by House Speaker Paul Ryan, editorial boards and legal watchdogs — can only inflame tensions out here. Curiel, the son of Mexican immigrants, was born in Indiana.

Despite the warning signs, there is little indication from the Trump campaign or anti-Trump demonstrators that they plan to change course, making continued unrest likely in the months ahead.

Tixier said Albuquerque is prepared if Trump returns during the general election campaign. “We’re not going to ask that he doesn’t come back here,” he said. “We welcome any presidential candidates.”

M. Scott Mahaskey contributed to this report.