A new national poll shows that former Vice President Joe Biden's long-held lead in the Democratic presidential primary may be evaporating, if it hasn't already disappeared.
The poll, released Monday by Monmouth University, shows Biden in third place behind Sens. Elizabeth Warren (D-Mass.) and Bernie Sanders (I-Vt.), presenting evidence that Biden's selling point as the most electable candidate isn't holding up well against his more progressive rivals.
Warren (20 percent), Sanders (20 percent) and Biden (19 percent) are essentially in a statistical tie — but it's Biden's drop from the previous poll that stands out.
Monmouth's June poll had Biden with a significant lead at 32 percent, followed by Warren at 15 percent and Sanders at 14 percent. No other candidate is in double figures in either poll.
The Monmouth poll results are based on a sample of 298 registered voters who identify as members of, or lean toward, the Democratic Party. Data was collected from Aug. 16-20 The poll has a 5.7 percent margin of error.
In the past two months, Biden has seen significant drops in support from white Democrats, minority voters, voters with and without a college degree, and voters both over and under the age of 50, with all that support shifting in equal quantity to Warren and Sanders.
Biden's biggest decline is seen among respondents in the later primary states, rather than the earlier ones which can have more influence over the way a primary progresses.
"Biden's drop in support is coming disproportionately from later states that have less impact on the process," said Patrick Murray, director of the independent Monmouth University Polling Institute. "But if this trend continues it could spell trouble for him in the early states if it undermines his claim to being the most electable candidate."
Murray said Warren is the candidate with the most momentum right now, and that Sen. Kamala Harris, although only polling at 8 percent, could still be seen as a contender due to her strength in early states.
Biden's campaign has been beset by numerous mistakes from the former vice president, raising questions about his mental sharpness and ability to handle the rigors of the campaign and go head-to-head with President Donald Trump in the general election.
"I want to be clear, I'm not going nuts," Biden felt compelled to tell a rally audience in New Hampshire, after an interview in which he appeared to think he was in Vermont.