Biden holds 28% support among Democrats and Democratic-leaning independents who are registered to vote, followed by Sanders at 17%, Warren at 14% and Buttigieg at 11%.

No other candidate reaches 4%, meaning the poll does not result in any changes to the lineup for the Democratic National Committee's December debate . A cluster of four candidates stand at 3%, including the latest entrant to the race, former New York City Mayor Michael Bloomberg. He is joined by Sen. Kamala Harris of California and businessmen Tom Steyer and Andrew Yang. Sens. Amy Klobuchar of Minnesota and Cory Booker of New Jersey have 2% each in the poll.

The findings suggest slight declines in support for Biden and Warren since October, and a modest increase in backing for Buttigieg. Sanders' support remains about the same as it was in October.

A majority of potential Democratic voters remain uncertain about their choices. Just 42% say they have definitely decided on their candidates, about the same as in October, and Biden continues to have an edge among that group of committed voters.

Asked who they would choose if the race came down to the top four instead of the 18 major candidates currently in the running, the order at the top remains the same. Biden continues to hold a lead -- 35% say they would choose him -- with 23% choosing Sanders, 20% Warren and 17% Buttigieg.

Buttigieg's bump in the poll coincides with a well-received debate performance , with 22% who watched or followed news coverage about last week's debate saying he had the best night. Biden lands in second at 16%, Sanders at 10%, Harris and Warren each at 8% and Booker at 5%.

Most potential Democratic voters say they prefer a candidate who aims for policies that have a good chance of becoming law, even if they wouldn't make major changes, over a candidate who aims for policies that would make larger changes (56% feel that way, 36% prefer a candidate who shoots for major change). But when asked which candidate would best handle specific issues, potential Democratic voters are more closely divided between those seeking big changes and those aiming for more incremental progress.

On health care, 28% say Sanders -- an advocate of "Medicare for All" and the elimination of private health insurance -- would best handle the issue. That's about even with the 26% who choose Biden, who has argued against moving to a completely government-run system. Another 19% say they prefer Warren's approach, which ultimately results in government health coverage for all, while 7% choose Buttigieg, and no other candidate has the backing of more than 3% on the issue.

Sanders leads the way more clearly on handling the climate crisis: 27% favor his approach, followed by 21% who prefer Biden and 15% Warren.

Biden holds an edge on the economy, though by a narrower margin than he did in October. About 3 in 10 (29%) prefer him on the issue, down from 38% last month, with Warren at 19% and Sanders at 17%. Buttigieg lands at 7% and Yang at 5% on the issue.

Biden has lost some ground as most trusted on almost all the issues tested, while Buttigieg has made gains nearly across the board.

More potential Democratic voters see Biden as capable of managing the government effectively (86%) than say the same about Sanders (73%), Warren (73%) or Buttigieg (54%). Biden also tops the leading candidates on being able to unite the country rather than divide it (73% say so, vs. 65% for Sanders, 58% for Warren and 54% for Buttigieg).

Sanders (66%), Biden (64%) and Warren (61%) are all closely clustered on being able to bring needed change, with Buttigieg a bit behind at 54%.

Warren holds a clear advantage on having the stamina and sharpness to be president -- 81% say that describes her, compared with 66% for Buttigieg, 65% for Biden and 58% for Sanders.

Sanders' strength is being seen as honest and trustworthy. Nearly 9 in 10 potential Democratic voters (89%) call Sanders honest and trustworthy, vs. 78% for Warren, 75% for Biden and 64% for Buttigieg. That carries through among all adults as well. Overall, 62% see Sanders as honest and trustworthy, making him the only candidate of the top four Democrats plus President Donald Trump who is seen that way by a majority of Americans.

All four tested Democratic candidates outpace Trump on two measures: honesty (62% Sanders, 49% Warren, 47% Biden, 45% Buttigieg, 36% Trump) and uniting the country rather than dividing it (47% Biden, 44% Sanders, 37% Warren, 35% Buttigieg, 31% Trump).

Trump ties Sanders at the top on being able to bring needed change (43% each, followed by Biden at 40%, Warren at 39%, Buttigieg at 35%). Biden leads the field on managing the government effectively (55% Biden, 46% Sanders, 44% Warren, 42% Trump, 36% Buttigieg). While Warren takes the lead on having the stamina and sharpness for the presidency (54% describe Warren that way, 47% Trump, 46% Buttigieg, 44% Biden and 40% Sanders).

One caveat on these figures: A large number (roughly a quarter across attributes) say they are unsure how to answer about Buttigieg. For the other candidates, that number was in the single digits across the board.

Health care (46% extremely important) and gun policy (44% extremely important) continue to rank at the top of voters' issue concerns for 2020. The impeachment inquiry into Trump ranks near the bottom, with 27% calling that extremely important. That rises a bit to 39% among Democrats and Democratic-leaning independent voters, but dips to just 15% among Republicans and Republican-leaning independent voters.