Two prominent liberal groups are moving to draft Sen. Elizabeth WarrenElizabeth Ann WarrenOn The Money: Trump 'ready' for tariffs on all 0B in Chinese goods | Trump digs in on Fed criticism | Lawmakers drop plans to challenge Trump ZTE deal On The Money: Trump rips Fed over rate hikes | Dems fume as consumer agency pick refuses to discuss border policy | Senate panel clears Trump IRS nominee Dems fume as Trump's consumer bureau pick refuses to discuss role in border policy MORE (D-Mass.) as a liberal alternative to Democratic presidential front-runner Hillary ClintonHillary Diane Rodham ClintonWhite House protests extend into sixth day despite rain Clinton: US is 'losing friends and allies' under Trump Justice Dept releases surveillance applications for former Trump aide MORE.

On Tuesday, announced its members would hold a vote on whether to spend $1 million to boost Warren in the Democratic primaries. The vote is expected to pass, with the group already saying it's poised to throw its "full weight" behind the Massachusetts Democrat.

Democracy For America, a group founded by former Vermont Gov. Howard Dean, a 2004 Democratic presidential candidate, announced shortly after it would join MoveOn’s efforts.

"Washington consultants can spout off a dozen reasons why Elizabeth Warren shouldn't run, but none of that beltway blather means a thing next to this one, simple truth: The Democratic Party and our country desperately need Warren's voice in the 2016 presidential debate,” DFA Executive Director Charles Chamberlain said in a statement.

"Senator Warren has deep grassroots support, an unwavering populist progressive vision, and the fearless fighting spirit needed to win the support of Democrats, Independents and Republicans,” he added.

Polls show Clinton, who has yet to declare a bid, as the runaway favorite for the Democratic nomination, with Warren typically registering a distant second or third, along with Vice President Biden.

Still, some on the left are clamoring for a progressive challenger to Clinton in the primaries. They believe Warren’s populist message is a stark contrast to Clinton’s close ties to Wall Street.

Warren has said publicly that she has no intention of running for president. Sen. Bernie Sanders (I-Vt.) has said he’s considering challenging Clinton, but polls indicate he wouldn’t be as formidable a challenger as Warren.

If Clinton were to shock political watchers and not pursue the White House, Warren would be under immediate pressure from progressive groups to run.