Vermont Sen. Bernie Sanders was back in California recently, trying to harness some of his popularity on behalf of progressive causes.

Sanders was here stumping for Proposition 61, the state initiative aimed at reducing prescription drug costs, and for San Francisco state Senate candidate Jane Kim.

Nearly 2.5 million Californians voted for Sanders in the Democratic primary.  Now, Sanders is calling on his supporters to back key issues -- and Democratic presidential nominee Hillary Clinton. But some Bernie backers are still making up their minds about that last ask.

Carroll Fife is one of them. She's involved with the Black Lives Matter movement and works to combat gentrification in Oakland. She was also a delegate for Sanders at the Democratic National Convention in July. Sure, she'll vote for Proposition 61. But ask Fife who she wants in the White House and she leans back and scrunches up her nose.

“Ouch, I don’t know!" she moans. "I would really have to think about that.”

Fife is no fan of Republican presidential nominee Donald Trump. But she’s not sold on Clinton either. Like many Bernie Sanders supporters in California, Fife has what some on the left call the “luxury” of living in a state where Clinton continues to have a formidable lead over Trump: She knows that even if she doesn't vote for Clinton, there's little danger Trump will win California's electoral votes.

Michael Kauffman is taking advantage of that. He’s a longtime supporter of the Peace and Freedom Party, but next month he’s voting for the Green Party’s presidential candidate, Jill Stein.

“If I were living in Ohio or Pennsylvania, I would be working very hard for Hillary Clinton without even holding my nose,” says Kauffman.

But some Bernie supporters say even if California is not a swing state, they want to make extra sure Trump is defeated. Tonya Love, an Oakland resident, will be voting for Clinton, “but at the same time recognizing you need to push her on things.”

Love, like many Sanders backers, is leery of Clinton’s connections to Wall Street and what she considers a hawkish foreign policy. Some Sanders voters also say Clinton is corrupt -- their suspicions further fueled by allegations that the Democratic Party was assisting her campaign on the sly during the primary.

“Hillary Clinton represents just about everything I oppose,” says Kate Tanaka, an Oakland real estate agent, who voted for Ralph Nader in the past.

Tanaka is returning to her political party roots and voting for the Green Party’s Stein. She doesn’t buy the notion that Clinton is the lesser of two evils and refuses to vote with a “gun to her head.”

“We have got to start having some choices in our elections,” says Tanaka.

But this middle-aged progressive isn’t yet ready to join up with Our Revolution, the organization Sanders launched after the convention and that brought him here last week in support of Proposition 61.

“I want to figure out what it is before I get involved with it,” says Tanaka.

Our Revolution came under criticism by some Sanders supporters because it can accept unlimited contributions without disclosing the donors.  That decision “dilutes the message” of Sanders’ grass-roots approach, says Mathew Murphy, an Oakland teenager and Sanders backer.

Murphy has not yanked the Bernie lawn sign still planted in his family’s front yard. "As you can see, we haven't really given up hope,” he says.

The 19-year-old is one of the prized millennials Clinton and the Democratic Party are desperately trying to turn out in November.

“I'm begrudgingly coming around to voting for Clinton,” says Murphy, whose brown hair is pulled back in a short ponytail.

As we talk in mid-September, Murphy is preparing to head off to college for his freshman year at UC Davis. As he carefully packs his clothes, he’s almost wistful about the primary and his luck as a first-time voter.

"It was really cool for the first election to vote for somebody that I really believed in," he says.

Murphy is somewhat deflated by Sanders’ loss. But he also makes it clear that he will not be sitting out this election -- in fact, he's looking forward to unpacking some of that Bernie activism at college.