Republican gubernatorial candidate John Cox doesn’t care that polls predict Democrat Gavin Newsom will trounce him in Tuesday’s election, because he’s “100 percent convinced that the people of this state want something different.”

“Polls are only as good as who you ask and how you ask it,” Cox said Tuesday in Vallejo at the start of a bus tour of the state.

Perhaps Cox was drawing hope based on the location of the charter school he toured Tuesday, MIT Academy High School. It’s on Positive Place.

He needs the good vibes because poll respondents are saying they prefer Newsom by overwhelming margins. A survey released this week by the nonpartisan organization Berkeley IGS indicated that 58 percent of likely voters support the lieutenant governor, compared with 40 percent for Cox. Only 2 percent remained undecided.

Newsom, who is on his own bus tour through the state, has led in all polls since the primary in June, when he was the top vote-getter and Cox finished second.

But Cox was undeterred, predicting a November surprise.

“Californians are famous for making their minds up at the last minute,” said the San Diego-area businessman, noting two Democratic candidates from years past who saw their poll leads evaporate on Election Day. “You can ask Gov. Tom Bradley or Gov. Kathleen Brown.”

Then, remembering that Bradley has been dead for 20 years, Cox said, “I’m not sure Mr. Bradley is with us still, but the point is California has had surprises in the past and I think they’re going to have another surprise this time.”

Cox said the polls “are underrepresenting the level of struggle” many Californians face in their daily lives.

“This is the Golden State,” he said. “People should enjoy their lives in this state, not work two or three jobs to be able to afford it. That’s what the political class represented by Gavin Newsom is going to continue. He’s going to double down on failure. He likes failure. I like success.”

Cox studiously avoided answering any questions about President Trump, whom he has credited with vaulting him into second place in the primary through a pre-election endorsement.

Trump tweeted in May that “California finally deserves a great Governor, one who understands borders, crime and lowering taxes. John Cox is the man — he’ll be the best Governor you’ve ever had.”

California finally deserves a great Governor, one who understands borders, crime and lowering taxes. John Cox is the man - he’ll be the best Governor you’ve ever had. I fully endorse John Cox for Governor and look forward to working with him to Make California Great Again! — Donald J. Trump (@realDonaldTrump) May 18, 2018

But Trump seems unlikely to follow up that late spring endorsement with a fall visit on behalf of Cox and GOP House candidates involved in competitive races in Orange County and the Central Valley.

Trump is campaigning for Republicans mostly in midwestern and southern states in the final days of the midterms campaign. Cox demurred Tuesday when asked whether the president would come here, but California is not on Trump’s itinerary.

Nor did Cox want to weigh in on Trump focusing his end-of-campaign efforts on trying to raise fears about a caravan of migrants that is hundreds of miles south of the U.S. border. Trump and other Republicans refer to the migrants, many of whom are traveling with little more than the clothes on their backs, as “invaders.”

California’s border security is one area where Cox and Newsom have diverged. Newsom wants to pull back 400 California National Guard troops dispatched to the Mexico border by Gov. Jerry Brown earlier this year at Trump’s request. Cox would leave them in place.

Cox’s response when asked about Trump and his message: “This election is about the future of California, about delivering a quality of life, about delivering better schools, affordable housing. That is what I’m focused on.

“I’m not running for president. Mr. Newsom wants to run for president — let him go ahead and do that. I’m focused on getting the job done here in California for struggling Californians who are already here and can’t afford a home or gasoline or electricity.”

Joe Garofoli is The San Francisco Chronicle’s senior political writer. Email: jgarofoli@sfchronicle.com Twitter: @joegarofoli