The latest query of voters from Monmouth University released Monday shows a virtual three-way tie between the top candidates. Sanders and Warren are each at 20%, compared to Biden who is at 19% among likely Democratic voters.

Sanders and Warren climbed six and five percentage points, respectively, compared to a similar Monmouth poll taken in June. Biden, who had a comfortable lead dipped 13 percentage points in that same poll from two months ago.

While Biden still remains atop many polls, the gap is narrowing between the former vice president and the other 20 or so Democratic presidential hopefuls. Additionally, several strategists and experts say Biden’s recent public gaffes might be catching up to him.

“As we move further into the election cycle you will likely see the poll numbers tighten,” said Brian Sobel, a San Francisco Bay Area political analyst. “While it’s true that Biden has been taking a lot of hits for his mistakes, it may lead to speculation whether he is competent to be president as some Democrats are not rushing to defend him because there still are so many candidates.”

Despite the misstatements that certainly will be “magnified,” Biden has some time recover, Sobel said.

“This is not the death blow. Biden needs to pay attention to what he says because his speaking off the cuff appears to be backfiring,” Sobel said. “He needs to be a lot more disciplined, and if he doesn’t, he’s going to continue to have these problems that may bite him.”

The latest Monmouth poll is also probably the best showing for Sanders, the Vermont senator who has been as low as fourth in most polls. The poll also shows a continued steady rise for Warren, the senator from Massachusetts, as well. Warren has also seen her favorability rating climb to 65% from 60% in May, according to the poll, while Sanders’ favorability rating has remained pretty steady at 64%, a slight dip from 65% three months ago.

Meanwhile, Biden has seen his favorability rating dropped to 66%, compared to 74% in May.

However, “it’s important to keep in mind this is just one snapshot from one poll,” said Patrick Murray, director of Monmouth’s Polling Institute. 

“The main takeaway from this poll is that the Democratic race has become volatile. 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,” Murray said. “But they are swinging more toward one of the left-leaning contenders with high name recognition rather than toward a lesser-known candidate who might be more in line with them politically.

“…But it does raise warning signs of increased churning in the Democratic nomination contest now that voters are starting to pay closer attention,” Murray added.

The Monmouth poll of just 298 registered voters who identify as Democrats or lean toward the Democratic Party, was taken between August 16-20. It has a smaller sample compared to other national polls, and a margin of error of plus or minus 5.7 percentage points. The findings reveal that Biden’s support fell sharply and broadly across key demographic groups, liberals, and moderates, white and nonwhite voters.

Among liberal voters, Warren not too surprisingly captured 24% of voters, with Sanders at 21%. Biden came in third at 15%, followed by California Senator Kamala Harris, who has seen a decline in polling since her consensus strong showing in the first debate at 11%. South Bend, Ind., Mayor Pete Buttigieg rounded out the top 5 with 5%.

Yet, Biden fared well with moderate and conservative Democratic voters with 22%, followed by Sanders at 20%, Warren at 16%, and Harris at 5%.

Biden also has a better showing with voters age 50 and older with 33%, compared to warren at 19% and Sanders at 11%. Buttigieg came in with 5%.

But, with voters under 50, Sanders is on top with 27%, followed by Warren (19%), Harris (12%), and Biden trailing with 6% and tying with tech entrepreneur Andrew Yang also with 6%. New Jersey Senator Cory Booker came in with 5%.

While the Democratic National Committee officially recognizes the Monmouth survey as a qualifying poll for the next two debates, Monday’s poll results have no effect on which candidates will qualify for next month’s crucial debate in Texas.  

More must-read stories from Fortune:

—Will gaffes hurt Biden’s chances of a 2020 win? Strategists are divided
—These are the 2020 senate races to watch
—What is BDS? Boycott, Divestment, and Sanctions explained
—When does Congress reconvene? August recess, explained
—Trump thinks he is winning the trade war, but the data tell a different story
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