Joe Biden Joe BidenFormer Pence aide: White House staffers discussed Trump refusing to leave office Progressive group buys domain name of Trump's No. 1 Supreme Court pick Bloomberg rolls out M ad buy to boost Biden in Florida MORE’s support in the race for the Democratic presidential nomination is slipping, according to a new survey from Monmouth University Poll that shows the former vice president dropping below 20 percent.

The survey showed Biden with support from 19 percent of Democratic and Democratic-leaning voters nationally, a double-digit decline from Monmouth's most recent poll in June when he led the pack with 32 percent.

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Now, the dynamics have changed, according to the Monmouth survey. Sens. Bernie Sanders Bernie SandersSirota reacts to report of harassment, doxing by Harris supporters Republicans not immune to the malady that hobbled Democrats The Hill's Morning Report - Sponsored by Facebook - Republicans lawmakers rebuke Trump on election MORE (I-Vt.) and Elizabeth Warren Elizabeth WarrenOvernight Defense: Appeals court revives House lawsuit against military funding for border wall | Dems push for limits on transferring military gear to police | Lawmakers ask for IG probe into Pentagon's use of COVID-19 funds On The Money: Half of states deplete funds for Trump's 0 unemployment expansion | EU appealing ruling in Apple tax case | House Democrats include more aid for airlines in coronavirus package Warren, Khanna request IG investigation into Pentagon's use of coronavirus funds MORE (D-Mass.), the primary field’s top progressive candidates, are each at 20 percent, putting them in a statistical tie with Biden and indicating a tightening three-way race.

Sen. Kamala Harris Kamala HarrisTexas Democratic official urges Biden to visit state: 'I thought he had his own plane' The Hill's Campaign Report: Biden on Trump: 'He'll leave' l GOP laywers brush off Trump's election remarks l Obama's endorsements A game theorist's advice to President Trump on filling the Supreme Court seat MORE (D-Calif.) was a distant fourth in Monday's poll, with 8 percent. Her level of support was unchanged from Monmouth's June survey.

South Bend, Ind., Mayor Pete Buttigieg Pete ButtigiegBillionaire who donated to Trump in 2016 donates to Biden The Hill's Morning Report - Sponsored by Facebook - GOP closes ranks to fill SCOTUS vacancy by November Buttigieg stands in as Pence for Harris's debate practice MORE, who has registered among the top contenders in polls for months, is now tied for fifth place with Sen. Cory Booker Cory Anthony BookerThe movement to reform animal agriculture has reached a tipping point Watchdog confirms State Dept. canceled award for journalist who criticized Trump 3 reasons why Biden is misreading the politics of court packing MORE (D-N.J.) at 4 percent.

Only four other candidates — former tech executive Andrew Yang Andrew YangBiden's latest small business outreach is just ... awful Doctor who allegedly assaulted Evelyn Yang arrested on federal charges The Hill's Campaign Report: Biden weighs in on police shootings | Who's moderating the debates | Trump trails in post-convention polls MORE, former Housing and Urban Development Secretary Julián Castro, former Rep. Beto O’Rourke (D-Texas) and bestselling author Marianne Williamson Marianne WilliamsonMarianne Williamson discusses speaking at People's Party Convention Fewer people watched opening night of Democratic convention compared to 2016 Marianne Williamson: Democratic convention 'like binge watching a Marriott commercial' MORE — garnered support form more than 1 percent of respondents in the poll.

Patrick Murray, director of the Monmouth University Polling Institute, said the latest survey results suggest the race for the Democratic nomination is entering a new phase.

“The main takeaway from this poll is that the Democratic race has become volatile,” Murray said. “Liberal voters are starting to cast about for a candidate they can identify with. Moderate voters, who have been paying less attention, seem to be expressing doubts about Biden.”

But instead of gravitating toward a lesser-known but more centrist-minded alternative, moderate voters “are swinging more toward one of the left-leaning contenders with high name recognition.”

Indeed, Biden has lost support among Democrats who identify as either moderate or conservative. In June, roughly 40 percent of those voters said they backed Biden’s bid for the nomination. Since then, that number has dropped to 22 percent.

There are signs that moderate and conservative Democrats are beginning to gravitate toward Sanders and Warren. Sanders saw his support among those voters jump from 10 percent to 20 percent over the past two months, while backing for Warren rose from 6 percent to 16 percent.

Since June, both Sanders and Warren have gained support overall, according to the Monmouth poll. Sanders gained 6 points in the latest survey, while Warren picked up 5 points.

At the same time, Warren has seen a noticeable uptick in favorability, climbing from 60 percent in May to 65 percent in August. Biden, on the other hand, saw his favorability drop from 74 percent to 66 percent during the same time period.

The Monmouth University Poll surveyed 298 registered voters who identify as Democrats or Democratic-leaning from Aug. 16-20. It has a margin of error of plus or minus 5.7 percentage points.