Sen. Elizabeth Warren (D-Mass.) has insisted she will not run in 2016, but that hasn’t stopped a grass-roots movement from trying to draft her into the race. (Bill O'Leary/The Washington Post)

Thirteen Iowa Democrats wearily took their seats here this weekend and discussed among themselves the source of their angst: Hillary Rodham Clinton.

“I’m utterly tired, tired of the Clintons and the whole establishment,” said Carol Brannon, 71, a retired nurse.

Anne Kinzel, 57, a former health-care lawyer, nodded sympathetically.

“The hacks think Hillary is entitled to be president,” Kinzel said. “I think she is one of those people who has lost the sense of why they are in politics.”

As Clinton prepares to launch her all-but-certain 2016 campaign, the former secretary of state remains a favorite of a vast majority of Democrats and the front-runner for the party’s presidential nomination. Still, there is unease among progressives about her largely uncontested ascent.

Seeking an alternative to the juggernaut, this restless Sunday gathering at the Ames public library and others like it are popping up around the country — all part of an effort to draft populist Sen. Elizabeth Warren (D-Mass.) into the race, in spite of her insistence that she will not be a candidate.

The grass-roots movement is being coordinated by Run Warren Run, a joint project of MoveOn.org and Democracy for America, two national groups that promote liberal causes and connect activists. In recent months, they have signed up about 250,000 supporters.

Over the course of the hour-long meeting, it was clear the frustrations of the attendees here were driven not only by Clinton but also by President Obama.

Eight years after Obama first drew enormous crowds in Iowa on his way to the White House, these Democrats feel disappointed by his presidency and what they described as his lackluster attempts to champion economic populism.

In Warren, they sense they’ve found a fighter and a refreshing departure from the way Obama and Clinton have addressed the rising gap between the rich and poor.

More deeply, they believe Warren channels their anger about the power of Wall Street banks.

“I remember going to the initial Obama rallies and I was inspired,” Bert Schroeder, 74, a retired social worker, said during a breakout session. “That was the first time I felt that way in years. I saw his crowds at the Hilton Coliseum at Iowa State and I thought, ‘Wow, this is our moment.’ ”

Raising his arms in exasperation, Schroeder asked, “What happened?”

“Should have done single-payer health care, should have done socialized medicine, should have taken on the banks,” replied David Brenner, 57, a botanist.

Directing the meeting was Adam Beaves, 24, a polished former Obama volunteer who was wearing a navy-blue Run Warren Run T-shirt. Whenever the conversation drifted away from Warren and toward Clinton, he tried to steer it back.

It wasn’t easy. The palpable disenchantment with Clinton dominated the comments even as Beaves emphasized that Run Warren Run is “focused on the positive.”

Beaves was repeatedly asked by the mix of white-haired grandparents and spiky-haired college students about whether Warren could actually be persuaded to run.

“If I just wanted to organize, there are many other places I could be,” Kinzel said.

Carolyn Klaus, a retired educator, asked, “Is our enthusiasm grounded in reality?”

“If we show her support on the ground, she will consider running for president,” Beaves told them. “If you look back to when she was drafted to run for Senate in Massachusetts, her answers were really similar to what she’s saying now. It’s not in her personality to get ahead of things.”

The small crowd murmured its approval.

Later, to give the drab setting a touch of celebrity, Beaves pulled out his laptop and played a video of actor Mark Ruffalo talking excitedly about Warren.

Ruffalo’s encouragement, watched in silence, won no applause. Beaves closed his computer quickly after it ended. In this blue-collar community, it’s Warren’s pitch and her working-class Oklahoma roots that connect, rather than her popularity in Hollywood.

“I don’t know what the heck will happen, but I’m going to put a ‘Draft Warren’ sign in my yard,” said Jerry Lamsa, another retiree. “Enough of the Clintons, enough of the Bushes. They can go — well, you know where I’d like to see them go.”

Lamsa and others at the meeting were willing to consider backing former Maryland governor Martin O’Malley (D), former senator Jim Webb (D-Va.) or Sen. Bernie Sanders (I-Vt.), all of whom will be in Iowa in coming months. Vice President Biden, who will be in Des Moines on Thursday, was not mentioned at all.

But for the moment, their hearts remain with Warren.

“The Democratic Party needs energy. It needs so much more energy, especially with my generation,” Allyson Bowers, 23, said.

Klaus said that if Warren doesn’t run, she may throw her support behind “Patrick O’Malley.”

When told his first name is Martin, she chuckled. “Martin O’Malley, Deval Patrick,” she said in reference to the former Massachusetts governor. “I don’t know.”