Donald Trump, Burlingame, California, April 29, 2016
In advance of the California primary election June 7, U.S. presidential candidate Donald Trump attempts to drum up support at the California Republican Party Convention in Burlingame April 29, 2016. Ramin Talaie/Getty Images

Protests targeting U.S. presidential candidate Donald Trump erupted in California on Friday for the second day in a row as the White House hopeful has moved closer to winning the Republican nomination after a string of victories this week. The billionaire businessman was forced to halt his motorcade and go through a back entrance to a hotel to give a speech at the California Republican Party Convention and avoid several hundred loud demonstrators gathered outside.

“That was not the easiest entrance I’ve ever made,” Trump told the gathering in Burlingame, south of San Francisco, after weaving around a barrier and clambering across a road to get to the venue. “It felt like I was crossing the border actually.”

Protesters, some of whom held Mexican national flags, at one point rushed security gates at the hotel and police officers had their batons out.

The candidate had already drawn demonstrations in California, with chaotic scenes outside a Trump rally in Costa Mesa Thursday. Anti-Trump protesters blocked traffic and smashed the window of a police patrol car, while some 20 people were arrested.

Demonstrations have become common outside rallies for Trump who has earned ardent critics, as well as support from Republican voters, for his rhetoric about illegal immigration. His campaign abandoned a rally in Chicago last month after clashes between his supporters and protesters.

Trump has accused Mexico of sending drug dealers and rapists across the U.S. border and has promised to build a wall and make Mexico pay for it.

The candidate, who described himself this week as the GOP’s presumptive nominee, would take a large stride toward knocking his Republican rivals out of the presidential race in the event he wins the Indiana primary election next week.

Trump said Friday he is approaching the 1,237 delegates needed to clinch the nomination. The candidate, who has run as a political outsider and only recently began making inroads to the Republican establishment, called for the party to band together behind him. But said he could win the White House without the establishment if necessary.

“There should be and there has to be unity. Now with that being said, would I win, can I win without it? I think so, to be honest,” Trump said at the state convention. His speech drew applause, although not the fervent reception of his usual campaign rallies.

Trump’s main rival, U.S. Sen. Ted Cruz of Texas, picked up Friday the backing of Gov. Mike Pence of Indiana in a rearguard battle to damage Trump’s chances. “I’m not against anybody, but I will be voting for Ted Cruz in the upcoming Republican primary,” Pence said on an Indiana radio show.

Cruz is trailing the former reality-TV star in the Midwestern state after losing to him by a wide margin in all five Northeastern states that held nominating contests Tuesday.

A CBS poll this week found Trump with about 40 percent support in Indiana, compared with Cruz’s 35 percent. The poll had a margin of error of 6.6 points. Other polls also have shown Trump leading there.

The Republican front-runner was in California ahead of its June 7 primary, when the most convention delegates of the Republican nominating cycle will be at stake.

After his speech, Trump made a similarly unconventional exit out of the hotel via the back door.

Cheryl McDonald, 71, of Discovery Bay, said she had to pass through demonstrators to get into the hotel. “They were yelling. I think the only words they know in the dictionary are profanity,” said McDonald, who indicated she is a Trump supporter.