Democratic presidential candidate Bernie Sanders greets people after speaking at a rally at Modesto Centre Plaza on June 2 in Modesto, Calif. (Matt McClain/ The Washington Post)

MODESTO, Calif. — Of the three remaining candidates running to represent the major parties, Sen. Bernie Sanders gives the most access to the traveling campaign press. He sits for interviews several times a day. He holds news conferences several times a week. There is just one caveat: If the press conference has a theme, he has a candidate's veto on off-theme topics, like whether he can win the Democratic nomination for president. Sanders, who has called the media "incapable" of covering an election seriously, likes to prove it.

Sanders began Thursday with a news conference in this city at the far north end of California's Central Valley. Reporters took places at the front of the room; local supporters and officials, including actress Susan Sarandon, filled out the rest. The purpose, ostensibly, was to ask front-runner Hillary Clinton to join his call for a carbon tax and to shine a spotlight on Donald Trump's science-challenged ruminations about the California drought, which he has mysteriously said he could end by turning "the water on."

"This is so ludicrous that it really would be funny if the future of the planet were not at stake," Sanders said. "Every person in California knows there’s a drought."

After 19 minutes of statements from himself and local allies, Sanders opened the floor.

"Any questions from the media on climate change?" he asked. "Got one on climate change? Not on the last poll?"

A reporter for the Modesto Bee fired off a question about the city council's recent resolution creating a "citizen's climate lobby."

"I can't tell you I'm very familiar with what they've done, but it sounds like movement in the right direction," Sanders said.

Next, while many reporters' hands stayed lowered, one of those council members — who had ambled out of the supporters' chairs and joined the press — asked "a question" that was more of a promotion of the city ("Don't leave without taking some of our almonds") and a recap of the climate vote.

"Congratulations," Sanders said. Asking only members of the media to pose questions, he fielded one about whether Clinton was one of the "head-in-the-sand" skeptics not taking climate change seriously enough.

"I did not, and you did not hear me, compare Secretary Clinton to Donald Trump," said Sanders. "Donald Trump is a climate change denier. He is rejecting science, [though] I do urge Secretary Clinton to be bolder. I want her to change her views on the very important issue of fracking."

The next question focused on Clinton, and whether she was presumptuous to pivot to attacking Trump at her high-profile San Diego speech. After Sanders gamely answered ("she can say whatever she wants"), he got a question about the courting of superdelegates.

"Are we off climate change now?" he asked. "Let me stay on climate change." After confirming that a photographer with his hand raised was, indeed, a reporter ("Are you with media?"), Sanders tore into a question about what sort of disaster it would take for skeptics to believe in climate change

"I think there have been a number of events! What you are seeing is not only the drought in California; you're not only seeing people unable to drink water coming out of their tap; you're not only seeing environmental disturbances."

After a few minutes, Sanders turned back to the superdelegates question. "And now we're on to the gossip!" he said. "Whatcha got? This is what really wakes you up."

Asked what he would do to convince superdelegates to join him after June 7, Sanders denied that he would "stump" in their states, but otherwise repeated his stump speech line that polls showed him more easily winning the general election.

That was it for climate change. MSNBC's Chris Jansing informed Sanders that Speaker of the House Paul D. Ryan (R-Wis.) had officially endorsed Trump. "What makes a lot of Democrats nervous is that there may be a divided convention," she said, asking if Democrats were right to blame him for any division.

"The logical corollary of what you're saying is that the people of California should not have a right to vote for president," snarked Sanders, as his supporters applauded. "I'm an old-fashioned guy. I kind of think democracy is a good idea. I believe in vigorous debate. More people involved in the political process will mean a higher voter turnout."

"But you'd likely to have to flip about 300 superdelegates," Jansing said.

"Look, Chris, I just gave you my answer on that one," Sanders said. "That's about it; I've got a rally to go to."

Sanders headed out, but one of the reporters who has been on his trail for months shouted that he "didn't really answer the question on superdelegates." Sanders stopped.

"I thought I answered," he said.

"Your two points are exactly the same as they've been for the last month, and yet there's zero evidence that superdelegates are starting to switch," she said. "So at some point, this is getting disingenuous."

"I don't think it's — I don't think it's disingenuous to say that the people of California have a right to determine who the Democratic nominee is, or the people of New Jersey," Sanders said. "Let the people speak, and let the superdelegates make their case."

He started to walk again, then turned around.

"And I hope you have as much passion about climate change," he said.