Many of the 1,000 people who attended Sen. Dianne Feinstein’s town hall Monday in San Francisco didn’t necessarily disagree with her; they just wanted her to be louder and more aggressive in opposing the Trump administration.

“We would like to see her represent her liberal constituency a lot more forcefully,” said Jegath Athilingam, 27, a neuroscience doctoral student at UC San Francisco. “We want to see her take the lead, as someone with her amount of seniority should do.”

At times, the hour-long constituent gathering at the Scottish Rite Masonic Center on 19th Avenue involved Feinstein trying to explain the rhythms of Washington’s slow-moving bureaucracy to an audience made up largely of people who are afraid, frustrated and angry at total Republican control of the government and want something done fast. Over the past five months, Feinstein’s office has received more than 2.5 million calls, emails and notes; typically, it receives 1 million in a year.

One man asked Feinstein, “to speak loudly and clearly, not just in your deliberative body but in public as much as you can. ... You have the ability to draw cameras just because you are Sen. Feinstein.”

While Feinstein was dropping Capitol Hill-speak phrases like “omnibus” — a bill that addresses multiple issues — and “CR” — continuing resolution, a type of appropriations legislation — audience members were demanding she speak out against the “fascists in the White House” and commit to a single payer health plan. “I’m not there yet” she said on single payer.

Many in the audience were associated with the San Francisco and East Bay chapters of Indivisible, the national anti-Trump network that has galvanized resistance efforts across the country. Yet aside from one persistent heckler, occasional shouts of “answer the question” and a rousing chorus of “single payer now,” the audience at what Feinstein staffers believe was her largest public town hall was fairly tame compared with what some of her colleagues have faced around the country.

A couple of attendees carried “Retire Feinstein!” signs, and one woman carried a poster urging U.S. Rep. Barbara Lee, D-Oakland, to challenge Feinstein when the senator’s term is up next year. Feinstein, who has been in office since 1992, has not said if she will seek re-election.

Yet while appreciative their senator showed up Monday to face her constituents, many were frustrated that Feinstein — famous for doing her homework before committing to a position — wouldn’t take more pointed, absolutist positions, like opposing everything Trump does.

“It was a little frustrating,” said Becky Shea, a Berkeley artist who is not part of Indivisible. She acknowledged the gap between the slow pace in Washington and the audience’s desire to see Feinstein pick up the pace and volume of her opposition.

“But I think there could be a happy medium somewhere between those two,” Shea said.

Illustrative of that disconnect was when San Franciscan Steve Rapport, who said his mother survived the Holocaust, asked Feinstein to speak out loudly against the “fascists” in the White House, including top presidential strategist Steve Bannon.

“We can’t normalize it,” Rapport said.

Feinstein listened, and said, “You’ve given me an idea. Let me explore that idea,” then said she would get back in touch with him. But she didn’t explain what her idea was.

The audience started jeering her, and many held up yellow signs made by Indivisible S.F. that said, “What are you doing about it?”

“Whoa, whoa, whoa, you’re pretty good at yelling,” Feinstein responded, trying to quiet the audience. “All of this takes a plan. You’ve got to work something out. You’ve got to have people with you. You can sit here and pound your fists, and I can show you what I’ve gotten done. And you can take a look at it. And I’d be surprised if you found too many senators, if any, that have gotten more done.

“I don’t get there by making statements I can’t deliver,” Feinstein continued. “ I get there through some caution, some discussion, some smart help, good lawyers, and we generally get where we’re going.”

But that wasn’t good enough for some in Monday’s audience.

“She’s been a gateway for the Trump administration,” said Ben Becker, who was holding a five-foot long fake check made out to Feinstein on behalf of the 8.75 million Californians who voted against Trump. The memo field on the check read: “What will it cost before you hear our voice?”

It didn’t seem to matter to Becker that Trump has yet to register a significant legislative win and that his approval rating is stuck in the low 40s, according to polls — he’s concerned about the impact he might have as president.

Trump nominee Judge Neil “Gorsuch got a lifetime appointment to the Supreme Court,” Becker said. “That’s not a nothing.”

The Feinstein camp knew who would be in Monday’s audience. In the lobby of the building, Feinstein aides posted 36 statements, position papers and opinion page pieces, most focused on how she has opposed Trump nominees (labeled “Feinstein on Trump nominees”) or taken stances different from the administration.

Not mentioned there were the nine Trump nominees she voted to confirm, including CIA Director Mike Pompeo, Homeland Security Secretary John Kelly and Defense Secretary James Mattis. A Feinstein aide said that given Trump’s lack of expertise in international and military policy, she wanted to surround the president with seasoned professionals.

Feinstein also responded to questions about Trump’s personal finances by saying the Senate Judiciary Committee, where she is the ranking Democrat, is looking at the emoluments clause of the Constitution. That section prevents office holders from accepting gifts from foreign leaders or governments and the committee wants to know “whether you can in fact deny certain federal payments for the business trips of his sons.”

Closer to home, she urged people to go “rustle up” Democrats to run against the 14 California Republicans in Congress. She was ticked that all 14 California GOP members wrote a letter to Transportation Secretary Elaine Chao asking her to put on hold a $647 million grant that was to help electrify Caltrain until a full audit is done on high-speed rail.

Democrats shouldn’t be scared off by well-funded GOP incumbents because “the times are volatile. Mistakes are being made. And there’s plenty that can be done” Feinstein said. But, to do that, she said, Democrats have to “go leave their area of comfort” to “work those valleys.”

As to her own plans, even though she is actively raising money — including at a fundraiser in San Francisco last week — Feinstein still has not made an announcement about whether she plans to seek re-election next year.

And there are lingering questions about her age. This month, 48 percent of the registered voters said it would be “a good thing for California” if Feinstein sought re-election, according to a Berkeley IGS Poll conducted by the Institute of Governmental Studies at UC Berkeley. But that figure dropped to 38 percent when voters were reminded that she will turn 84 this year.

Feinstein, who stood for the entire town hall meeting while answering questions, did not address the re-election issue. And it was one of few pointed questions she was not asked about.

Perhaps the best news for those in attendance was hearing Feinstein commit to holding another town hall on a Saturday during the summer recess — a time, they said more of her constituents could attend, as opposed to 11 a.m. on a Monday.

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