Sen. Elizabeth WarrenElizabeth Ann WarrenTrump on 2020 Dems skipping AIPAC: 'I think they're anti-Jewish' The Hill's Morning Report — Washington readies for Mueller end game 2020 Dems avoid this year's AIPAC conference MORE (D-Mass.) received a standing ovation at a progressive conference in Washington on Thursday, as the left continues to urge her to run for president in 2016.

“Run, Elizabeth, run!” they chanted, as one supporter asked her whether she’d launch a presidential campaign.

"I appreciate the thought," Warren told the crowd, smiling. "I am not running for president."

Her well-received speech at the liberal Campaign For America’s Future (CAF) conference only underscores liberals’ growing frustration in finding an alternative to all but undeclared frontrunner and former secretary of State Hillary Clinton.

Progressive groups such as CAF, which helped launch then-Sen. Barack Obama's 2008 presidential campaign, have become increasingly more vocal about their concerns with Clintons' economic policies.

They say former President Bill Clinton's deregulatory policies in the 1990s helped contribute to the 2008 economic collapse, and question the Clintons' ties to Wall Street donors.

"Hillary Clinton, if she decides to run, should be talking about the kinds of issues we've been talking about today," said CAF co-founder Roger Hickey in an interview. "There are a lot of things that she hasn't clarified." 

Last week, the Clintons offered an unapologetic defense of their economic policies in separate Washington speeches. Hillary, for her part, praised her husband’s economic record, while criticizing former President George Bush. 

Bill was more forthright. 

"Everybody acts like I sat in a closet and said, 'What can I do for Wall Street today?'" the former president said at the Peter G. Peterson Foundation’s 2014 Fiscal Summit last week.

The so-called “Elizabeth Warren wing of the Democratic party” has yet to find their candidate. Warren has insisted she’s not running. But other contenders lack her appeal to the base.

Earlier Thursday, The Wall Street Journal reported that former Montana Democratic Gov. Brian Schweitzer was interested in running as a progressive alternative to Clinton. And Maryland Gov. Martin O’Malley as well as Sen. Bernie Sanders (I-Vt.) are also considered to be mulling a run. 

“I think anybody that you mention at this point sounds unlikely to make a dent,” Hickey said. “Scheitzer apparently wants to run. And my view is that some competition in the party so that there are some debates in the primaries is a really good thing. Schweitzer could do it. Gov. O’Malley could do it. Any number of people could do it.”

Warren, for her part, has insisted she’s not interested. Last October, she joined every Democratic female Senator in signing a letter of support for a Clinton White House bid.

Still, Warren, Sanders and Sen. Sherrod Brown (D-Ohio) each made their case during their remarks for the Democratic Party to move more to the left.

"During the financial crisis, I would say the single issue we've pushed the hardest on was — in return for the tens of billions of dollars that was shoveled in for these biggest financial institutions — a little accountability," Warren told the crowd. "What we got — and I want to be clear and this was under both administrations — was nothing, nothing and nothing out of that."

Brown made a similar case during his remarks: “The national Democrats haven't gotten the message, from the president on down, that you need to be a populist party."

Sanders, an independent who is often counted as a Democrat, has said that he'd be interested in challenging Clinton if she runs for president. He made no mention of his 2016 plans in his remarks, and any Clinton challenger faces a steep uphill climb. 

"If it takes a challenger not to coast to the nomination without explaining who she is and what she stands for — a challenger is a very useful thing," Hickey said. "It's healthy for the party, and it's helpful for her ability to campaign in the general election if she's nominated."

Hickey said that progressives are frustrated that Obama seemingly “gave up … except rhetorically” after his stimulus plan to advocate for more government spending.

"My view is that some competition in the party so that there are some debates in the primaries is a really good thing," Hickey said. "The Democrats need a jobs and a growth plan. They can't just pretend that this recovery is good for everybody." 

Asked if he's asked Warren to run, Hickey said: "I personally have not, but many people have."