SAN FRANCISCO — With a week to go before the June 5 primary, Lt. Gov. Gavin Newsom is vowing not to run for president if elected governor, dismissing criticism about his campaign tactics, and suggesting he’d take a more activist role in legislative debates than Gov. Jerry Brown.

As Newsom’s new campaign bus — emblazoned with his first name and a big blue bear — inched through traffic on Highway 101 from San Francisco to San Jose on Tuesday morning, the candidate squeezed into the plush seats for a wide-ranging interview with reporters. It was the first leg of a bus tour that his campaign says will criss-cross the state in the last week before the June 5 primary.

“We are taking nothing for granted,” Newsom said, despite his leading position in the polls.

But the lieutenant governor has faced increasingly loud criticism in recent weeks from his campaign rivals and other Democrats who accuse him of hurting the party by elevating Republican businessman John Cox, the governor candidate who was endorsed by President Trump. Newsom’s campaign has been running ads highlighting Cox’s opposition to gun control, likely raising his appeal among conservatives, in an apparent bid to help Newsom face a Republican candidate in November. The top two candidates, regardless of party affiliation, will go from the primary to the general.

Gavin Newsom kicks off statewide bus tour this morning at SF City Hall, one week from #CAGov primary. “I want to bring back that sense of idealism” from the 60s, he says pic.twitter.com/EU6i0hewih — Casey Tolan (@caseytolan) May 29, 2018

Many political observers have predicted that having two Democrats in the November general election — along with the U.S. Senate race — would benefit the party by depressing GOP turnout. That could help Democratic candidates in key congressional races up and down the state that may determine whether Democrats retake the House of Representatives nationally. The national liberal website ThinkProgress wrote last week that Newsom was “tossing his fellow Dems under the bus” by helping Cox get past the primary.

But Newsom argued that an intra-party duel between him and another Democrat in November would actually hurt the pary, draining financial resources from the Congressional races and other key down-ballot fights. His candidacy, he said, was “a moment of opportunity to unite the Democratic Party — and when Democrats are united, we always win.”

His campaign rivals blasted that argument as self-serving. “The truth is, Gavin is responsible for propping up Donald Trump’s candidate and hurting Democrats’ chances of taking back the House because he’s afraid of any competition this fall,” said Fabien Levy, a spokesman for State Treasurer John Chiang. “That’s not courage, that’s cowardice.”

“This is a man who will justify just about anything that is in his personal political interests,” added Luis Vizcaino, a spokesman for former Los Angeles Mayor Antonio Villaraigosa.

Newsom also didn’t sound too worried about facing Cox in November. “John Cox driving huge turnout? I don’t see that,” he said.

“We plan to give Gavin Newsom all he can handle, and he will have to answer for eight years of Democrat mismanagement,” responded Cox spokesman Matt Shupe.

In the interview, Newsom also vowed that he wouldn’t jump ship in Sacramento to run for president in 2020 or 2024 if he was elected governor. “It’s not even of passing interest to me, none,” he said. “The minute you have your eye elsewhere, you’re not doing justice to the people of this state.”

He said he’d learned from Gov. Jerry Brown’s advice that he got more done during his last two terms, when he was focused only on California, as compared to his first two terms in the ’70s and ’80s, when he was preparing for a run to be leader of the free world.

.@GavinNewsom commits not to run for president during the next four/eight years if elected governor. Says he learned from @JerryBrownGov, who got more done during his last two terms when he wasn’t running for prez pic.twitter.com/SxAQCvZFyO — Casey Tolan (@caseytolan) May 29, 2018

As the bus made its way past the campuses of Facebook and Google, Newsom promised to engage the tech industry to help address the state’s housing shortage. Tech leaders have “a unique responsibility and role to play in that issue,” Newsom said. “Because of their success, the unintended consequence is that cost of living has gone through the roof.”

He suggested that big tech firms should be investing more of the money they repatriated under the new federal tax law into housing for middle-income workers, instead of using the windfall to “advantage a lot of these tech leaders and their stockholders.” If he wins, he said one of his first calls would be to Apple CEO Tim Cook, for a “conversation” about housing issues.

Newsom praised Brown for “creating a new norm of expectation in terms of fiscal discipline,” one he said he’d follow. But he added that he’d be more engaged on and more willing to spend more state money on issues of higher education, workforce development, and early childhood education than Brown’s administration.

The lieutenant governor also suggested he’d take a more activist approach to legislative debates than Brown has. The governor generally keeps his cards close to his vest on which bills he’ll sign or oppose, except for a few fights over major legislation that he throws himself into each year.

“I’m going to pull a lot more things into the governor’s office and not just let them fester in the legislature,” Newsom said. “There are certain issues that I think require the governor’s office to be more proactive on the front end, as opposed to engaged in the backend,” including homelessness and health care reform, he said.