Bernie Sanders spoke at Santa Barbara City College on Saturday. (Photo by Matt McClain/The Washington Post)

BAKERSFIELD, Calif. — Bernie Sanders’s opponent in the California Democratic presidential primary is Hillary Clinton. That’s what the ballot says, anyway. But listening to the Vermont senator on the campaign trail here, you’d hardly know it.

At Santa Barbara City College Saturday morning, Sanders spoke to a crowd of 6,000 people for almost an hour without so much as mentioning the former secretary of state. When he finally did, it was only briefly.

“I am proud to tell you that I have introduced the most comprehensive climate change legislation ever introduced in the Senate, which among other things calls for a tax on carbon,” Sanders said. “And I hope very much that Secretary Clinton would join me in telling the fossil fuel industry that what they are doing is unacceptable.”

Moments later, he highlighted his total opposition to fracking, adding “that is not Secretary Clinton’s view, and I hope she changes her mind on that.”

From there, Sanders pivoted to the subject of universal health care. That was it for the Clinton references.

Later, stumping at the Kern County Fairgrounds in Bakersfield, Sanders spoke for 33 minutes before invoking Clinton.

“One difference between Secretary Clinton and me is I do not have — and never will have — a super PAC,” he said. He brought her up only once more, when he repeated the fracking line from earlier in the day.

Meanwhile, Sanders laced his speeches with sharp critiques of Republicans, generally, and presumptive GOP presidential nominee Donald Trump, specifically. Barring a historic comeback in the final stages of the Democratic primary, Sanders won’t get to run against Trump.

He won’t even get to debate Trump, now that the real estate mogul has backed off his previous statement that he would “love” to face Sanders before Californians vote on June 7. Sanders repeatedly challenged Trump to change his mind on Saturday — “if he has any guts.”

Sanders’s decision to mostly ignore his actual adversary can be viewed two different ways. He continues to argue publicly that he can still win the Democratic nomination, despite Clinton’s virtually insurmountable delegate lead. Acting on the stump as if Clinton hardly exists could be seen as just another example of blocking out reality.

But it could also be seen as a tacit acknowledgment of reality — evidence that Sanders is trying not to inflict further rhetorical damage on Clinton, even as he campaigns all the way to the wire.

Subtle hints support the latter interpretation. In Santa Barbara, Sanders told supporters “this campaign is about reinvigorating American democracy. It’s stopping the move toward oligarchy, where a handful of billionaires control the political process.”

One goal he didn’t mention? Winning.

He was a bit bolder in Bakersfield — with a little goading from the audience. At one point, he began a sentence with a hypothetical: “If I’m elected president … .” The crowd reacted with mild applause. “All right,” Sanders conceded. “When I’m elected president … .” The crowd erupted.

Free from the sway of a live audience, Sanders regained his restraint. In an excerpt of an interview on “Meet the Press” that NBC released ahead of its airing on Sunday, he entertained the idea that he won’t top the Democratic ticket. He even offered his opinion of the kind of running mate Clinton should choose.

“I would hope, if I am not the nominee,” Sanders said, “that the vice presidential candidate will not be from Wall Street, will be somebody who has a history of standing up and fighting for working class families, taking on the drug companies whose greed is doing so much harm, taking on Wall Street, taking on corporate America, and fight for a government that works for all of us, not just the 1 percent.”

Sanders was particularly hard on Trump in Bakersfield, a mostly conservative city of about 380,000 that one local campaign volunteer described as “a piece of Texas in California.” Indeed, the stage for Sanders’s rally was set up in a dirt arena that more often hosts rodeos. In the background, under a temporary banner that read, “a future to believe in,” a permanent sign said, “Stotler Swine Pavilion.”

Sanders somehow resisted the temptation to joke about cutting pork-barrel spending in Washington.

Going hard after Trump here seemed designed to discourage backers who might consider flipping to the other self-styled political outsider in the race, should Clinton become the Democratic standard-bearer. In a Washington Post-ABC News poll last week, 20 percent of Sanders supporters said they plan to vote for Trump in November.

Sanders didn’t tell the crowd to vote for Clinton; he’s still running against her, after all, even if he seldom says her name. But he made clear his belief that the roughly 3,000 people in the house should not vote for Trump under any circumstances.

“Donald Trump will not become president of the United States because we will not allow him to become president.”